Patent Publication Number: US-2011060877-A1

Title: External storage device, control method for computer system, control method for external storage device, and computer program product

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the priority based on Japanese Patent Application No. 2009-192854, of Buffalo inc. filed on Aug. 24, 2009, the disclosure of which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present invention relates to an external storage device for connection to a computer system that includes a display device; to a control method for a computer system; to a control method for an external storage device; and to a computer program. 
     2. Related Art 
     External storage devices designed to connect to computer systems have enjoyed widespread use for some time. Some types of external storage devices are furnished with multiple physical or logical storage portions. In one embodiment, a removable media device has a virtual CD-ROM area and a storage area. 
     When an external storage device with multiple storage portions is connected to a computer system, the computer system recognizes each storage portion as an individual disk drive, and assigns an individual drive letter to each storage portion. Thus, a drive tree and icons representing the multiple disk drives are displayed on the display device of the computer system. The user is then able to view and perform various operations on the drive tree and icons that are displayed on the display device to represent the disk drives (storage portions). 
     In an external storage device having multiple storage portions, some of the storage portions may store computer programs that are executed only at specific times, for example when the external storage device is initially connected to a computer system, and that after being executed once are substantially never executed thereafter. Examples of such programs are an installer for application software, and utility software for configuring initial settings of the external storage device. In such instances, where a drive tree and icons representing storage portions that store computer programs which are virtually never used are displayed on the display device of the computer system, the user viewing and attempting to perform various operations may experience poor ease of use. 
     An advantage of some aspects of the invention is to ameliorate cumbersome operation for the user when presented with display of a drive tree and icons representing multiple storage portions on a display device when an external storage device containing the storage portions is connected to a computer system that includes the display device. 
     SUMMARY 
     The present invention is addressed to attaining the above objects at least in part according to the following aspects of the invention. 
     According to one aspect of the invention, there is provided: 
     An external storage device for connection to a computer system, comprising: 
     a first storage portion storing a first computer program; and 
     a second storage portion, wherein 
     the first computer program is to be executed by the computer system after a first drive letter is assigned to the first storage portion by the computer system, and 
     the first computer program includes: 
     a portion for directing the computer system to automatically delete the first drive letter assignment for the first storage portion without a Delete instruction by a user at prescribed timing while the external storage device is connected to the computer system. 
     In addition to the aspect of an external storage device described above, the present invention may assume the aspect of a control method for a computer system including a connected external storage device, or a control method for an external storage device. Additional possible aspects include a computer program for realizing the above, a recording medium having the computer program recorded thereon, or a data signal containing the program and carried on a carrier wave. The supplemental elements shown above may be implemented in these respective aspects as well. 
     Where the present invention is provided as a computer program or a recording medium having the computer program recorded thereon, it may constitute the entire program for controlling operations of the external storage device or of the computer system storing the external storage device, or only that portion used to carry out the functions of the present invention. Various computer-readable media may be employed as the recording medium, such as a flexible disk, CD-ROM, DVD-ROM, magnetooptical disk, IC card, ROM cartridge, printed matter imprinted with symbols such as a bar code, computer internal memory devices (memory such as RAM and ROM), and external memory devices. 
     These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  depicts the general features of a computer system according to a first embodiment of the invention; 
         FIG. 2  is a flowchart illustrating the flow of a process executed by a CPU  110  of a personal computer  100  when a hard disk drive  200  is initially connected to the personal computer  100 ; 
         FIG. 3  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when initial configuration application software is run the second or subsequent time, with the hard disk drive  200  connected to the personal computer  100 ; 
         FIG. 4  depicts the general features of a computer system according to a second embodiment of the invention; 
         FIG. 5  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when a hard disk drive  200 A is connected to the personal computer  100 ; 
         FIG. 6  depicts the general features of a computer system according to a third embodiment of the invention; 
         FIG. 7  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when a hard disk drive  200 B is initially connected to the personal computer  100 ; 
         FIG. 8  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when the hard disk drive  200 B is accessed the second or subsequent time; 
         FIG. 9  depicts the general features of a computer system according to a fourth embodiment of the invention; and 
         FIG. 10  is a flowchart illustrating the flow of processes executed by the CPU  110  of the personal computer  100  and by the CPU of a controller  210 C of a hard disk drive  200 C when the hard disk drive  200 C is initially connected to the personal computer  100 . 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENT 
     A fuller understanding of the aspects of the invention is provided by the following description of the embodiments. 
     A. First Embodiment 
     A1. System Configuration 
       FIG. 1  depicts the general features of a computer system according to a first embodiment of the invention. This computer system includes a hard disk drive  200  having a cable connection to a personal computer  100  through a USB (Universal Serial Bus) cable for example. 
     The personal computer  100  includes a CPU  110 , a hard disk drive  120 , and a display device  130 . Under the management of the operating system (OS), the CPU  110  performs overall control of the personal computer  100  and executes different application software. The personal computer  100  corresponds to the computer system recited in the Summary. 
     The hard disk drive  200  includes a controller  210  and a storage portion  220 . The controller  210  is furnished with a CPU, RAM, ROM and so on (not shown), and controls reading of data from the storage portion  220  and writing of data to the storage portion  220  (hard disk drive area  224 ). The storage portion  220  is composed of several hard disks, and includes a logically partitioned virtual CD-ROM drive area  222  and a hard disk drive area  224 . The virtual CD-ROM drive area  222  is recognized as a CD-ROM drive by the personal computer  100  when the hard disk drive  200  is connected to the personal computer  100 . The personal computer  100  then assigns a drive letter (e.g. “F:”) to the virtual CD-ROM drive area  222 . The hard disk drive area  224  is recognized as hard disk drive by the personal computer  100  when the hard disk drive  200  is connected to the personal computer  100 . The personal computer  100  then assigns a drive letter (e.g. “G:”) to the hard disk drive area  224 . A drive tree and icons representing the CD-ROM drive (virtual CD-ROM drive area  222 ) and the hard disk drive (hard disk drive area  224 ) are then displayed on the display device  130 . The hard disk drive  200  corresponds to the external storage device recited in the Summary. 
     Application software for use in initial configuration is stored in the virtual CD-ROM drive area  222 . This initial configuration application software is discussed later. The initial configuration application software is loaded and run by the CPU  110  of the personal computer  100  at a specific time, for example, when the hard disk drive  200  is initially connected to the personal computer  100 . Once the initial configuration application software is executed, it is substantially never executed again thereafter. 
     The initial configuration application software includes, for example, a device configuration utility, a RAID (Redundant Arrays of Inexpensive Disks) configuration utility, a driver installer, an application software installer, and so on; these are run through the agency of a launcher designed to run them. When a drive letter is assigned to the virtual CD-ROM drive area  222  by the personal computer  100 , the launcher runs automatically through the Auto-Run feature of the OS. The initial configuration application software also includes auxiliary application software; as discussed later, this auxiliary application software installs automatically onto the hard disk drive  120  of the personal computer  100  when the virtual CD-ROM drive area  222  is initially assigned a drive letter by the personal computer  100 . The functions of the auxiliary application software are discussed later. The virtual CD-ROM drive area  222  corresponds to the first storage portion recited in the Summary. The auxiliary application software included in the initial configuration application software corresponds to the first computer program recited in the Summary. The device configuration utility, RAID configuration utility, a driver installer, an application software installer, etc. included in the initial configuration application software correspond to the second computer program recited in the Summary. In the present embodiment, the virtual CD-ROM drive area  222  also stores drivers and application software for installation on the personal computer  100  by the installers that are included in the initial configuration application software. 
     The hard disk drive area  224  is used as a rewritable area. The hard disk drive area  224  corresponds to the second storage portion recited in the Summary. 
     A2. Process 
       FIG. 2  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when the hard disk drive  200  is initially connected to the personal computer  100 . 
     When the hard disk drive  200  is initially connected to the personal computer  100 , the CPU  110  first recognizes the virtual CD-ROM drive area  222  and the hard disk drive area  224  as a CD-ROM drive and a hard disk drive, respectively (Step S 100 ). The CPU  110  then assigns respective drive letters to the virtual CD-ROM drive area  222  and the hard disk drive area  224  (Step S 110 ). At this time, the CPU  110  records information relating to the drive letter assignments as drive letter information in the registry. 
     Next, using the Auto-Run function of the OS, the CPU  110  automatically runs the initial configuration application software (launcher) stored in the virtual CD-ROM drive area  222  (Step S 120 ), and accepts commands from the user. In this way the initial configuration application software may be run without the user having to enter an initial configuration application software Run command into the personal computer  100 , thus affording enhanced user convenience. 
     Then, according to commands from the user, the CPU  110  performs various processes such as initial device configuration, RAID configuration, and installation of drivers and application software (Step S 130 ). At this time the CPU  110  also installs the auxiliary application software on the hard disk drive  120 . When the process of Step S 130  is completed, the CPU  110  executes the auxiliary application software to delete and disable the drive letter assignment for the virtual CD-ROM drive area  222  through a function of the auxiliary application software (Step S 140 ). Deletion of the drive letter assignment for the virtual CD-ROM drive area  222  is accomplished by deleting the information relating to the drive letter assignment for the virtual CD-ROM drive area  222  from the drive letter information described in the registry. Disabling of drive letter assignment for the virtual CD-ROM drive area  222  is accomplished by prohibiting information relating to the drive letter assignment for the virtual CD-ROM drive area  222  from the drive letter information from being described in the registry. The CPU  110  then terminates the process. 
     Through the above process, the branch in the drive tree and icon representing the virtual CD-ROM drive area  222  no longer appear on the display device  130 . Even if the personal computer  100  is restarted with the hard disk drive  200  connected to the personal computer  100 , assignment of a drive letter to the virtual CD-ROM drive area  222  is disabled, and because no drive letter is assigned to the virtual CD-ROM drive area  222 , no branch in drive tree or icon representing the virtual CD-ROM drive area  222  is displayed on the display device  130 . 
       FIG. 3  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when the initial configuration application software is run the second or subsequent time, with the hard disk drive  200  connected to the personal computer  100 . 
     When the user enters a command to execute the auxiliary application software from the Start Menu of the OS, the CPU  110  runs the auxiliary application software which was installed previously onto the hard disk drive  120  from the virtual CD-ROM drive area  222  (Step S 200 ), and through a function of the auxiliary application software re-enables drive letter assignment for the virtual CD-ROM drive area  222 . The CPU  110  then assigns a drive letter to the virtual CD-ROM drive area  222  (Step S 210 ). 
     Next, the CPU  110  runs the initial configuration application software stored in the virtual CD-ROM drive area  222  (Step S 220 ), and accepts commands from the user. Then, according to commands from the user, the CPU  110  performs various processes such as initial device configuration, RAID configuration, and installation of drivers and application software (Step S 230 ). When the process of Step S 230  is completed, the CPU  110  executes the auxiliary application software to again delete and disable drive letter assignment for the virtual CD-ROM drive area  222  through a function of the auxiliary application software (Step S 240 ) in the same manner as in Step S 140  of  FIG. 2 . The CPU  110  then terminates the process. 
     Through the above process, after the drive letter assignment for the virtual CD-ROM drive area  222  is deleted in the personal computer  100 , it is possible for the virtual CD-ROM drive area  222  to be reassigned a drive letter and to be deleted again the drive letter assignment. Accordingly, no branch in the drive tree or icon representing the virtual CD-ROM drive area  222  is displayed on the display device  130  after the completion of the process of Step S 230 , even when the user or some application software requires the OS to display the drive tree and icons representing the multiple disk drives included in the system. 
     According to the computer system of the first embodiment described above, when the hard disk drive  200  furnished with the virtual CD-ROM drive area  222  and the hard disk drive area  224  is connected to the personal computer  100 , it is possible to hide the branch in the drive tree and icon representing the virtual CD-ROM drive area  222 , which need not be displayed on the display device  130 , even when the user or some application software requires the OS to display the drive tree and icons representing the multiple disk drives included in the system. This ameliorates cumbersome operation for the user when presented with display of a drive tree and icons representing multiple drive areas on the display device. The user may be provided with enhanced convenience as a result. 
     B. Second Embodiment 
     B1. System Configuration 
       FIG. 4  depicts the general features of a computer system according to a second embodiment of the invention. The configuration of this computer system differs from that in the first embodiment in that the hard disk drive  200  is replaced by a hard disk drive  200 A. The hard disk drive  200 A is of encrypted hard disk type. 
     The hard disk drive  200 A includes a controller  210 A and a storage portion  220 . The controller  210 A includes an encryption/decryption module  212 , and is adapted to decrypt data while reading the data from the storage portion  220 , and to encrypt data while writing data to the storage portion  220  (hard disk drive area  224 ). The encryption/decryption module  212  may be implemented through hardware, or implemented through software. The storage portion  220  includes a virtual CD-ROM drive area  222  and a hard disk drive area  224 . 
     In the hard disk drive  200 A of the second embodiment, the virtual CD-ROM drive area  222  stores an authentication tool and auxiliary application software. The authentication tool is a piece of utility software for carrying out password authentication. In the password authentication, an authentication process to determine if a user who wishes to access the hard disk drive  200 A is an authorized user is performed. In the present embodiment, password authentication is employed for the authentication process. The authentication tool corresponds to a second computer program recited in the Summary. 
     As in the first embodiment, the auxiliary application software in the second embodiment has the function of deleting the assignment of a drive letter to the virtual CD-ROM drive area  222 . However, in contrast to the first embodiment, the auxiliary application software in the second embodiment does not have the function of disabling assignment of a drive letter to the virtual CD-ROM drive area  222 . 
     B2. Process 
       FIG. 5  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when the hard disk drive  200 A is connected to the personal computer  100 . 
     When the hard disk drive  200 A is connected to the personal computer  100 , the CPU  110  first recognizes the virtual CD-ROM drive area  222  as a CD-ROM drive (Step S 300 ). The CPU  110  then assigns a drive letter to the virtual CD-ROM drive area  222  (Step S 310 ). At this time, the CPU  110  records information relating to the drive letter assignment as drive letter information in the registry. In the present embodiment, recognition of the hard disk drive area  224  and assignment of a drive letter thereto in Steps S 300  and S 310  are not carried out in contrast to Steps S 100  and S 110  the first embodiment. 
     Next, using the Auto-Run function of the OS, the CPU  110  automatically runs the authentication tool stored in the virtual CD-ROM drive area  222  (Step S 320 ), and accepts input of a password by the user. The CPU  110  performs password authentication on the basis of the input password (Step S 330 ), and if authentication fails (Step S 330 : NO), displays on the display device  130  an error message indicating failed authentication (Step S 332 ). The CPU  110  then terminates the process. 
     On the other hand if authentication is successful (Step S 330 : YES), the CPU  110  recognizes the hard disk drive area  224  as a hard disk drive (Step S 340 ), and assigns a drive letter to the hard disk drive area  224  (Step S 350 ). At this time, the CPU  110  records information relating to the drive letter assignment as drive letter information in the registry. Through this feature, until authentication is successful, the hard disk drive area  224  is not assigned a drive letter and the user cannot access the hard disk drive area  224 . Thus, only an authorized user can access the hard disk drive area  224 . 
     Next, the CPU  110  runs the auxiliary application software (Step S 360 ), and through a function of the auxiliary application deletes the drive letter assignment for the virtual CD-ROM drive area  222  (Step S 370 ). The CPU  110  then terminates the process. The branch in the drive tree and icon representing the virtual CD-ROM drive area  222  are thus no longer displayed on the display device  130 , even when the user or some application software requires the OS to display the drive tree and icons representing the multiple disk drives included in the system. 
     According to the computer system of the second embodiment described above, when the hard disk drive  200 A having the virtual CD-ROM drive area  222  and the hard disk drive area  224  is connected to the personal computer  100 , it is possible to hide the branch in the drive tree and icon representing the virtual CD-ROM drive area  222 , which need not be displayed on the display device  130 . This ameliorates cumbersome operation for the user when presented with display of a drive tree and icons representing multiple drive areas on the display device. The user may be provided with enhanced convenience as a result. 
     C. Third Embodiment 
     C1. System Configuration 
       FIG. 6  depicts the general features of a computer system according to a third embodiment of the invention. In this computer system configuration, the hard disk drive  200 A of the second embodiment is replaced by a hard disk drive  200 B. Like the hard disk drive  200 A, the hard disk drive  200 B is of encrypted hard disk type. The functions of the various parts of the hard disk drive  200 B are identical to those of the hard disk drive  200 A. 
     In the hard disk drive  200 B of the third embodiment, the virtual CD-ROM drive area  222  stores an authentication tool installer, in addition to an authentication tool and auxiliary application software. The authentication tool is identical to that in the second embodiment. The auxiliary application software is identical to that in the first embodiment. 
     C2. Process 
       FIG. 7  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when the hard disk drive  200 B is initially connected to the personal computer  100 . 
     When the hard disk drive  200 B is initially connected to the personal computer  100 , the CPU  110  executes processes identical to Step S 300  and Step S 310  in  FIG. 5  (Steps S 400 , S 410 ). 
     Next, using the Auto-Run function of the OS, the CPU  110  automatically runs the authentication tool installer stored in the virtual CD-ROM drive area  222 , and installs the authentication tool on the hard disk drive  120  (Step S 420 ). According to this feature, the authentication tool can be run on the personal computer  100  end even after the drive letter assignment for the virtual CD-ROM drive area  222  has been deleted in the personal computer  100 . Once installation of the authentication tool is complete, the CPU  110  runs the auxiliary application software (Step S 430 ), and deletes and disables letter assignment for the virtual CD-ROM drive area  222  (Step S 440 ). The CPU  110  then terminates the process. 
     Through the above process, the branch in the drive tree and icon representing the virtual CD-ROM drive area  222  are no longer displayed on the display device  130 . Even if the personal computer  100  is restarted with the hard disk drive  200 B connected to the personal computer  100 , no drive letter is assigned to the virtual CD-ROM drive area  222 , so no branch in the drive tree or icon representing the virtual CD-ROM drive area  222  is displayed on the display device  130 . 
       FIG. 8  is a flowchart illustrating the flow of a process executed by the CPU  110  of the personal computer  100  when the hard disk drive  200 B is accessed the second or subsequent time. 
     When the user enters an authentication tool Run command from the Start Menu of the OS, the CPU  110  runs the authentication tool that was previously installed onto the hard disk drive  120  from the virtual CD-ROM drive area  222  (Step S 500 ), and accepts input of a password by the user. The CPU  110  then performs password authentication on the basis of the input password (Step S 510 ), and if authentication fails (Step S 510 : NO), displays on the display device  130  an error message indicating failed authentication (Step S 512 ). The CPU  110  then terminates the process. 
     On the other hand if authentication is successful (Step S 510 : YES), the CPU  110  recognizes the hard disk drive area  224  as a hard disk drive (Step S 520 ), and assigns a drive letter to the hard disk drive area  224  (Step S 530 ). At this time, the CPU  110  records information relating to the drive letter assignment as drive letter information in the registry. The CPU  110  then terminates the process. Through this feature, until authentication is successful, the hard disk drive area  224  is not assigned a drive letter and the user cannot access the hard disk drive area  224 . Thus, only an authorized user can access the hard disk drive area  224 . 
     According to the computer system of the third embodiment described above, when the hard disk drive  200 B having the virtual CD-ROM drive area  222  and the hard disk drive area  224  is connected to the personal computer  100 , it is possible to hide the branch in the drive tree and icon representing the virtual CD-ROM drive area  222 , which need not be displayed on the display device  130 . This ameliorates cumbersome operation for the user when presented with display of a drive tree and icons representing multiple drive areas on the display device. The user may be provided with enhanced convenience as a result. 
     D. Fourth Embodiment 
     D1. System Configuration 
       FIG. 9  depicts the general features of a computer system according to a fourth embodiment of the invention. In this computer system configuration, the hard disk drive  200  of the first embodiment is replaced by a hard disk drive  200 C. 
     The hard disk drive  200 C includes a controller  210 C and a storage portion  220 . The controller  210 C is furnished with a CPU, RAM, ROM and so on (not shown), a LUN (Logical Unit Number) management module  214 , and a command reception module  216 . As depicted in model form in the drawing, the LUN management module  214  uses a LUN table  214   t  to manage information relating to the logical unit number of the virtual CD-ROM drive area  222  and the logical unit number of the hard disk drive area  224 . The command reception module  216  receives commands issued by the personal computer  100 . The process that employs these elements is discussed later. The LUN table  214   t  is stored in the EEPROM included in the controller  210 C. 
     As in the first embodiment, the virtual CD-ROM drive area  222  in the hard disk drive  200 C of the fourth embodiment stores initial configuration application software, etc. When the hard disk drive  200 C is initially connected to the personal computer  100 , the initial configuration application software is loaded and executed by the CPU  110  of the personal computer  100 . The initial configuration application software in the fourth embodiment includes an Issue Command program in place of the auxiliary application software in the initial configuration application software of the first embodiment. This Issue Command program is a computer program that directs the CPU  110  of the personal computer  100  to issue a command to delete the information relating to the logical unit number of the virtual CD-ROM drive area  222  from the LUN table when the CPU  110  has completed various processes using the initial configuration application software. The hard disk drive area  224  is identical to that in the first embodiment. 
     D2. Process 
       FIG. 10  is a flowchart illustrating the flow of processes executed by the CPU  110  of the personal computer  100  and by the CPU of the controller  210 C of the hard disk drive  200 C when the hard disk drive  200 C is initially connected to the personal computer  100 . The process executed by the CPU  110  of the personal computer  100  is shown at left in the drawing, and the process executed by the CPU of the controller  210 C of the hard disk drive  200 C is shown at right in the drawing. 
     When the hard disk drive  200 C is initially connected to the personal computer  100 , first, the CPU  110  of the personal computer  100  executes the processes of Steps S 100  to S 120  depicted in  FIG. 10 . These processes are identical to the processes of Steps S 100  to S 120  shown in  FIG. 2 . Then, according to commands from the user, the CPU  110  performs various processes such as initial device configuration, RAID configuration, and installation of drivers and application software (Step S 130 C). At this time, unlike the process of Step S 130  in  FIG. 2 , the CPU  110  does not install the auxiliary application software on the hard disk drive  120 . When the CPU  110  completes the process of Step S 130 C, it then executes the Issue Command program, and issues a command to delete the information relating to the logical unit number of the virtual CD-ROM drive area  222  from the LUN table (Step S 132 ). 
     When the command reception module  216  of the hard disk drive  200 C receives the command (Step S 600 ), the LUN management module  214  deletes the information relating to the logical unit number of the virtual CD-ROM drive area  222  from the LUN table (Step S 610 ). Thus, if the personal computer  100  is restarted with the hard disk drive  200 C connected to the personal computer  100 , the personal computer  100  cannot recognize the virtual CD-ROM drive area  222  and does not assign a drive letter to the virtual CD-ROM drive area  222 , so no branch in the drive tree or icon representing the virtual CD-ROM drive area  222  is displayed on the display device  130 . 
     According to the computer system of the fourth embodiment described above, when the hard disk drive  200 C containing the virtual CD-ROM drive area  222  and the hard disk drive area  224  is connected to the personal computer  100 , it is possible to hide the branch in the drive tree and icon representing the virtual CD-ROM drive area  222 , which need not be displayed on the display device  130 . This ameliorates cumbersome operation for the user when presented with display of a drive tree and icons representing multiple drive areas on the display device. The user may be provided with enhanced convenience as a result. 
     E. Variations 
     The present invention may be addressed according to the following aspects of the invention. 
     [First Aspect] 
     According to first aspect of the invention, there is provided: 
     An external storage device for connection to a computer system, comprising: 
     a first storage portion storing a first computer program; and 
     a second storage portion, wherein 
     the first computer program is to be executed by the computer system after a first drive letter is assigned to the first storage portion by the computer system, and 
     the first computer program includes: 
     a portion for directing the computer system to automatically delete the first drive letter assignment for the first storage portion without a Delete instruction by a user at prescribed timing while the external storage device is connected to the computer system. 
     When the external storage device according to the first aspect is connected to a computer system that includes a display device, the computer system recognizes the first storage portion as a first disk drive, and assigns a first drive letter to the first storage portion. Subsequently, once the computer system loads and executes the first computer program stored in the first storage portion, the first drive letter assignment in the computer system to the first storage portion is deleted automatically. Thus, a branch in the drive tree and icon representing the first storage portion is no longer displayed on the display device. That is, the present aspect ameliorates cumbersome operation for the user when presented with display of a drive tree and icons representing multiple storage portions on a display device, when an external storage device containing the storage portions is connected to a computer system that includes the display device. The user may be provided with enhanced convenience thereby. 
     In the present aspect, the first storage portion and the second storage portion are mutually different storage portions. Prescribed timing refers to a point in time coming after display of a branch in drive tree and icon representing the first storage portion on the display device is no longer necessary; different timing arrangements may be set up according to how the external storage device is used. The first computer program may be stored in the first storage portion in a format that can be loaded and executed directly by the computer system, or stored in the first storage portion in a compressed format. 
     [Second Aspect] 
     According to second aspect of the invention, there is provided: 
     The external storage device according to the first aspect wherein 
     the first computer program further includes: 
     a portion for directing the computer system to disable assignment of the first drive letter to the first storage portion by the computer system. 
     According to this feature, if the computer system is restarted while the external storage device is connected to the computer system for example, no first drive letter is assigned to the first storage portion, and thus no branch in the drive tree and icon representing the first storage portion is displayed on the display device. 
     [Third Aspect] 
     According to third aspect of the invention, there is provided: 
     The external storage device according to the first or second aspect wherein 
     the first storage portion further stores a second computer program, wherein 
     the second computer program is to be executed by the computer system after the first drive letter is assigned to the first storage portion by the computer system but before the first computer program is executed by the computer system, and 
     the second computer program includes: 
     a portion for directing the computer system to perform a prescribed process in relation to the external storage device according to an instruction from the user, and 
     the prescribed timing is a timing subsequent to completion of the prescribed process. 
     According to this feature, the drive letter assignment to the first storage portion may be deleted after the computer system loads and executes a second computer program stored in the first storage portion, and a prescribed process is completed in the computer system. 
     Examples of prescribed processes include utility software, an installer for application software, initial configuration of the external storage device, authentication processes, and so on. The second computer program may be stored in the first storage portion in a format that can be loaded and executed directly by the computer system, or stored in the first storage portion in a compressed format. 
     [Fourth Aspect] 
     According to first aspect of the invention, there is provided: 
     The external storage device according to the third aspect wherein 
     the second computer program is a computer program automatically run by the computer system after the external storage device is connected to the computer system and the first drive letter is assigned to the first storage portion. 
     According to this feature, the second computer program may be run without the user inputting a Run command for the second computer program into the computer system, thus affording improved convenience for the user. 
     [Fifth Aspect] 
     According to first aspect of the invention, there is provided: 
     The external storage device according to the third or fourth aspect wherein 
     the second computer program further includes: 
     a portion for directing the computer system to recognize the second storage portion as a second disk drive and to assign a second drive letter to the second storage portion, after the computer system carries out the prescribed process. 
     According to this feature, assignment of a second drive letter to the second storage portion does not take place, that is, the user cannot access the second storage portion, until the computer system completes the process. 
     [Sixth Aspect] 
     According to first aspect of the invention, there is provided: 
     The external storage device according to the fifth aspect wherein 
     the prescribed process includes an authentication process to ascertain whether the user is an authorized user. 
     According to this feature, only an authorized user can access the second storage portion. Examples of authentication processes are password authentication, biometric authentication, IC card authentication, and various other authentication methods. 
     [Seventh Aspect] 
     According to first aspect of the invention, there is provided: 
     The external storage device according to any of the third to seventh aspects wherein 
     the second computer program further includes: 
     a portion for directing the computer system to install at least some of functions of the second computer program to the computer system. 
     According to this feature, even after the first drive letter assignment for the first storage portion is deleted in the computer system, at least some of the functions of the second computer program may be run on the computer system end. 
     [Eighth Aspect] 
     According to first aspect of the invention, there is provided: 
     The external storage device according to the seventh aspect including the features of the third and aspects wherein 
     the some of the functions includes: 
     a function for directing the computer system to re-enable to assign the first letter drive to the first storage portion after execution of the first computer program. 
     According to this feature, after the first drive letter assignment for the first storage portion is deleted in the computer system, the first drive letter assignment may be reassigned to the first storage portion. 
     [Ninth Aspect] 
     According to first aspect of the invention, there is provided: 
     An external storage device for connection to a computer system, comprising: 
     a first storage portion; 
     a second storage portion, wherein 
     a management portion adapted to manage information relating to a logical unit number of the first storage portion; and information relating to a logical unit number of the second storage portion, using a table, wherein 
     at prescribed timing after the first storage portion is recognized as a first disk drive and the first storage portion is assigned a first drive letter by the computer system, the management portion deletes the information relating to the logical unit number of the first storage portion from the table. 
     According to this feature, in the event that the computer system is restarted with the external storage device connected to the computer system for example, the branch in the drive tree and icon representing the first storage portion cease to be displayed on the display device. That is, the present aspect ameliorates cumbersome operation for the user when presented with display of a drive tree and icons representing multiple storage portions on a display device when an external storage device containing the storage portions is connected to a computer system that includes the display device. The user may be provided with enhanced convenience thereby. 
     [Tenth Aspect] 
     According to first aspect of the invention, there is provided: 
     The external storage device according to the ninth aspect further comprising: 
     a command reception portion adapted to receive from the computer system a command to delete the information relating to the logical unit number of the first storage portion, wherein 
     the prescribed timing is timing subsequent to reception of the command by the command reception portion. 
     According to this feature, the management portion may delete information relating to the logical unit number of the first storage portion, at a point in time subsequent to the command reception portion having received the command from the computer system. 
     [Eleventh Aspect] 
     According to first aspect of the invention, there is provided: 
     The external storage device according to the tenth aspect wherein 
     the first storage portion stores a computer program, wherein 
     the computer program is to be executed by the computer system after the first drive letter is assigned to the first storage portion by the computer system, and 
     the computer program includes: 
     a portion for directing the computer system to carry out a prescribed process in relation to the external storage device, according to an instruction from a user; and 
     a portion for issuing the command when the prescribed process is completed. 
     According to this feature, when the computer system loads and executes the computer program stored in the first storage portion, and the process is completed in the computer system, the computer may then issue the command. Examples of prescribed processes include utility software, an installer for application software, initial configuration of the external storage device, authentication processes, and so on. 
     F. Modified Examples 
     While the invention is disclosed above in terms of certain preferred embodiments, it is to be understood that there is no intention to limit the invention to the embodiments disclosed herein, and that various other modes are possible within the spirit and scope of the invention. Modifications such as the following are possible, for example. 
     F1. Modified Example 1 
     In the preceding embodiments, in Step S 120  shown in  FIG. 2  for example, the CPU  110  automatically runs the initial configuration application software, but the invention is not limited to this arrangement. The CPU  110  may instead run the initial configuration application software in response to a user command. This applies to automatically running software in the other embodiments as well. 
     F2. Modified Example 2 
     The features of the hard disk drives  200 ,  200 A,  200 B in the preceding first to third embodiments may be combined appropriately. For example, the virtual CD-ROM drive area  222  of the hard disk drive  200 A in the second embodiment or the virtual CD-ROM drive area  222  of the hard disk drive  200 B in the third embodiment may be designed to store the initial configuration application software in the first embodiment. In the third embodiment, the auxiliary application software may be installed together with the authentication tool on the personal computer  100 . 
     F3. Modified Example 3 
     The various software applications included among the initial configuration application software in the first and fourth embodiments may be modified appropriately. 
     F4. Modified Example 4 
     In the preceding second and third embodiments, password authentication is employed as the authentication process, but the invention is not limited thereto. Other authentication technologies such as biometric authentication or IC card authentication could be implemented in place of password authentication. 
     F5. Modified Example 5 
     In the preceding first to third embodiments, the CPU  110  deletes the drive letter assignment for the virtual CD-ROM drive area  222  subsequent to installation of the application software and completion of processes such as the authentication process, but the invention is not limited thereto. The CPU  110  may delete the drive letter assignment for the virtual CD-ROM drive area  222  without a Delete command by the user, at any time while the hard disk drive  200 ,  200 A,  200 B is connected to the personal computer  100 . 
     F6. Modified Example 6 
     In the preceding embodiments, the storage portion  220  of the hard disk drive  200  is furnished for example with a virtual CD-ROM drive area  222  and a hard disk drive area  224 , but the invention is not limited thereto. The storage portion  220  may be provided with a plurality of logical or physical storage portions. 
     F7. Modified Example 7 
     In the preceding embodiments, the external storage device of the invention was implemented in a hard disk drive, but the invention is not limited thereto. The external storage device of the invention may be implemented in other types of external storage device such as a USB memory, SSD (Solid State Drive), or multifunction device, rather than a hard disk drive. 
     F8. Modified Example 8 
     Some of the features implemented through hardware in the preceding embodiments could be replaced by software, and conversely some of the features implemented through software could be replaced by hardware. 
     F9. Modified Example 9 
     The Program product may be realized as many aspects. For example: 
     (i) Computer readable medium, for example the flexible disks, the optical disk, or the semiconductor memories;
 
(ii) Computer including the computer readable medium, for example the magnetic disks or the semiconductor memories; and
 
(iii) Computer temporally storing the computer program in the memory through the data transferring means.
 
     F10. Modified Example 10 
     While the invention has been described with reference to preferred exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments or constructions. On the contrary, the invention is intended to cover various modifications and equivalent arrangements. In addition, while the various elements of the disclosed invention are shown in various combinations and configurations, which are exemplary, other combinations and configurations, including more less or only a single element, are also within the spirit and scope of the invention.