Abstract:
An enclosure of an information processing apparatus is designed to enclose a processor. An opening is defined in the enclosure. The opening is designed to guide insertion and removal of a storage device. The user is allowed to easily attach and detach the storage device such as a hard disk drive to and from the enclosure. The user may simply own a single storage device for plural enclosures. Various information related to the operating conditions is stored in the storage device. If the user is allowed to operate the information processing apparatuses solely based on the single storage device, the accustomed operating conditions can always be established for plural information processing apparatuses.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to an information processing apparatus comprising a processor such as a central processing unit (CPU) and a storage device such as a hard disk drive (HDD).  
         [0003]     2. Description of the Prior Art  
         [0004]     In general, various information is read out of a hard disk drive (HDD) in a computer system during the processing. The operating conditions are determined based on the read information. Since the HDD is enclosed in an enclosure of a computer, the identical operating condition cannot be realized in different computers unless the information is transferred to a computer from another computer. The increased volume of information affecting the operating conditions makes it difficult to realize the common operating condition for different computers.  
         [0005]     The reduced volume of a computer enables a user to tote a computer at hand. In this case, it is sufficient for a user to own a single computer. If a user is allowed to solely operate only own computer, the user can always enjoy the accustomed operating conditions. However, the reduced volume of a computer also makes the screen of an accompanied display and a keyboard smaller. The maneuverability gets worse.  
         [0006]     The HDD usually holds programs for establishing the operating conditions, application programs, unique data of a user, and the like. The unique data of the user should be prevented from leakage. The unique data of the user is preferably protected from inspection of someone else. In general, a certificate data such as a password is utilized to protect the unique data from leakage and inspection. The input certificate data is compared with the registered certificate data prior to access to the data within the HDD. This check is troublesome to the user. In addition, the certificate data may possibly be looked through. Even when a certificate data has been registered, the unique data cannot reliably be protected in some cases.  
       SUMMARY OF THE INVENTION  
       [0007]     It is accordingly an object of the present invention to provide an information processing apparatus contributing to an improvement of operating conditions without deterioration of the maneuverability. It is also an object of the present invention to provide an information processing apparatus contributing security of data stored within a storage device.  
         [0008]     According to a first aspect of the present invention, there is provided an information processing apparatus comprising: an enclosure enclosing at least a processor; and an opening defined in the enclosure, said opening designed to guide insertion and removal of a storage device.  
         [0009]     The information processing apparatus allows the user to easily attach and detach the storage device such as a hard disk drive to and from the enclosure. The user may simply own a single storage device for plural enclosures. In general, various information related to the operating conditions is stored in the storage device such as a hard disk drive. If the user is allowed to operate the information processing apparatuses solely based on the single storage device, the accustomed operating conditions can always be established for plural information processing apparatuses. It should be noted that any storage device other than the hard disk drive may be utilized as the aforementioned storage device.  
         [0010]     The above-described information processing apparatus may be utilized to establish a so-called desktop computer system. It is possible to avoid reduction in the size of the screen of the display device and the keyboard in the desktop computer system. A superior maneuverability can be obtained. In addition, the storage device such as a hard disk drive can be lighter and smaller than a general small computer such as a notebook personal computer system, so that the user is allowed to easily tote the storage device at hand.  
         [0011]     According to a second aspect of the present invention, there is provided an information processing apparatus comprising: an enclosure enclosing at least a processor, wherein a storage device is attachable to and detachable from the enclosure, said storage device storing program instructions booting the processor.  
         [0012]     In general, an operating system program is stored in a hard disk in a hard disk drive, for example. Unless the hard disk drive is installed in the information processing apparatus, the operating system cannot be booted. The information within the hard disk can be read out from the hard disk only if the operating system has been booted. The removal of the hard disk drive out of the enclosure of the information processing apparatus enables restriction of the booting of the operating system in a facilitated manner. A sufficient security can be established. In this case, the hard disk in the hard disk drive may be designated as the boot drive in the information processing apparatus.  
         [0013]     In any event, the user is allowed to simply own a single storage device or hard disk drive for plural enclosures. Accordingly, if the user is allowed to operate the information processing apparatuses solely based on the single storage device in the aforementioned manner, the accustomed operating conditions can always be established for plural information processing apparatuses. The information processing apparatus of the type can be utilized to establish a desktop personal computer system in the same manner as described above.  
         [0014]     According to a third aspect of the present invention, there is provided an information processing apparatus comprising: an enclosure enclosing at least a processor; an interface channel utilized to connect the processor with a primary storage device; an opening defined in the enclosure so as to receive insertion of a storage device; and a connector connected to the interface channel and connected to the storage device inserted through the opening.  
         [0015]     In general, an operating system program is stored in a recording medium of a storage device, such as a hard disk in a hard disk drive. Unless the hard disk drive is connected to the interface channel, the operating system cannot be booted. Without the booting of the operating system, the information within the hard disk cannot be read out. Removal of the hard disk drive out of the enclosure of the information processing drive enables restriction of the booting of the operating system in a facilitated manner. A sufficient security can be established. In this case, the hard disk in the hard disk drive may be designated as the boot drive in the information processing apparatus.  
         [0016]     In any event, the user is allowed to simply own a single storage device or hard disk drive for plural enclosures. Accordingly, if the user is allowed to operate the information processing apparatuses solely based on the single storage device in the aforementioned manner, the accustomed operating conditions can always be established for plural information processing apparatuses. The information processing apparatus of the type can be utilized to establish a desktop personal computer system in the same manner as described above.  
         [0017]     In any of the aforementioned information processing apparatuses, a memory may be connected to the processor. The memory preferably stores a primary identification data designed to define a primary identifier and a booting program for boot of the information processing apparatus. The processor operates to compare a secondary identifier with the primary identifier based on the booting program. The secondary identifier may be included in a secondary identification data obtained from the storage device or hard disk drive. Based on the comparison, the processor determines the validity of the storage device inserted into the enclosure of the information processing apparatus. The information processing apparatus may prohibit the accessibility to the storage device unless the storage device is determined to be valid. A specific combination of the information processing apparatus and the storage device can be established in this manner. The credibility of the security can be improved.  
         [0018]     The processor may determine based on the comparison between the primary and secondary identifiers whether or not the processor boots the operating system stored in the storage device or hard disk drive. In this case, the booting of the operating system can be prohibited unless the storage device or the hard disk drive is determined to be valid to the information processing apparatus. The credibility of the security can further be improved.  
         [0019]     It is preferable to restrict the accessibility to the primary identification data and/or the secondary identification data in the information processing apparatus and/or the storage device. Only the booting program or BIOS program should be allowed to have the accessibility. The restricted accessibility leads to a higher creditability of the security. In particular, the overwriting is preferably prohibited on the primary identification data. This prohibition of the overwriting prevents the replacement of the primary identifier with a specific secondary identifier. A further restriction can be achieved to boot the operating system based on the readout from the storage device. Additionally, the primary and/or secondary identifiers may be stored in a memory or the hard disk drive after encryption.  
         [0020]     A storage device or hard disk drive is provided for realizing the aforementioned information processing apparatus. The storage device or hard disk drive may comprise: a storage medium or hard disk storing an operating system program; an inner enclosure enclosing the storage medium; a printed circuit board at least partly exposed at the outer surface of the inner enclosure; and an outer enclosure covering over the printed circuit board at the outer surface of the inner enclosure. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     The above and other objects, features and advantages of the present invention will become apparent from the following description of the preferred embodiment in conjunction with the accompanying drawings, wherein:  
         [0022]      FIG. 1  is a perspective view illustrating a specific example of a desktop computer system;  
         [0023]      FIG. 2  is an exploded perspective view of a computer in the desktop computer system;  
         [0024]      FIG. 3  is an exploded perspective view schematically illustrating the structure of a hard disk drive (HDD);  
         [0025]      FIG. 4  is a plan view schematically illustrating the inner structure of the HDD;  
         [0026]      FIG. 5  is a block diagram illustrating the structure of electronic components in the computer;  
         [0027]      FIG. 6  is a block diagram illustrating the concept of recording areas on a hard disk in the HDD;  
         [0028]      FIG. 7  is a flowchart schematically illustrating the processing of a central processing unit (CPU) in the computer in accordance with the description of a basic input/output system (BIOS) program;  
         [0029]      FIG. 8  is a flowchart illustrating the processing of the CPU in the booting of an operating system (OS); and  
         [0030]      FIG. 9  is a flowchart illustrating the processing of the CPU for establishment of a secondary identifier. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]      FIG. 1  illustrates a desktop computer system  11  as a specific example of an information processing apparatus. A display device  12  and input devices such as a keyboard  13  and a mouse  14  are connected to a computer  15  in the desktop computer system  11 . The display device  12  is allowed to display images, including texts, on the screen based on image data supplied from the computer  15 . The user can input various instructions and information data into the computer  15  through the input devices  13 ,  14 .  
         [0032]     The computer  15  includes an enclosure  16  enclosing at least a central processing unit (CPU). An opening  18  is defined in the front panel of the enclosure  16 . The opening  18  is designed to receive insertion of a mass storage or hard disk drive (HDD)  17 . As is apparent from  FIG. 1 , the HDD  17  can be inserted into the inner space of the enclosure  16  through the opening  18 . The front end of the HDD  17  may remain out of the front panel of the enclosure  16  as illustrated. The display device  12  may be integral to the enclosure  16  of the computer  15  as a notebook personal computer system, for example.  
         [0033]     Recording medium drives such as a flexible disk drive (FDD)  19  and a CD-ROM (Compact Disk Read Only Memory) drive  21  are also enclosed within the enclosure  16  of the computer  15 . The FDD  19  and the CD-ROM drive  21  are allowed to receive a diskette (FD)  22  and a CD-ROM medium  23 , respectively, through receiving openings defined in the front panel of the enclosure  16 . The FDD  19  and the CD-ROM drive  21  read data and/or software programs out of the diskette  22  and CD-ROM medium  23 , respectively.  
         [0034]     As shown in  FIG. 2 , a motherboard  25  is placed within the enclosure  16  of the computer  15 . The aforementioned CPU  26  is mounted on the motherboard  25 . The CPU  26  executes software programs such as a basic input/output system (BIOS), an operating system (OS), application softwares, and the like. The CPU  26  may stationarily be surface mounted on the motherboard  25  based on soldering or else. Alternatively, the CPU  26  may detachably be mounted on the motherboard  25  through a so-called CPU slot stationarily surface mounted on the motherboard  25 .  
         [0035]     A HDD mounting bay  27  is further placed within the enclosure  16 . When the HDD  17  is received on the HDD mounting bay  27  in the enclosure  16 , the rear end of the HDD  17  faces the bottom  28  of the HDD mounting bay  27 . Connectors  29 ,  31  for IDE data and power supply are fixed to the bottom  28 . A power supply unit  32  is connected to the connector  31  for power supply. Electric power from the power supply unit  32  is distributed to the motherboard  25 , the connector  31  for power supply, the FDD  19 , the CD-ROM drive  21 , and other electronic devices. A pair of guide rails  33  are formed on the HDD mounting bay  27 . The guide rails  33  extend along a horizontal plane from the opening  18  to the bottom  28 .  
         [0036]     As shown in  FIG. 3 , the HDD  17  includes an inner enclosure  34  enclosing a mass storage medium, namely a hard disk (HD). A printed circuit board  35  get exposed at the outer surface of the inner enclosure  34 . Connectors  36 ,  37  for IDE data and power supply, in addition to electronic circuits such as a hard disk controller and the like, are mounted on the printed circuit board  35 . The hard disk controller is designed to manage the overall operation of the HDD  17 .  
         [0037]     The inner enclosure  34  is enclosed within an outer enclosure  38   a,    38   b.  The outer enclosure includes a first half shell  38   a  and a second half shell  38   b  coupled with each other. The outer enclosure  38   a  covers over the printed circuit board  35  at the outer surface of the inner enclosure  34 . Openings  39 ,  41  are defined in the outer enclosure  38   a.  The openings  39 ,  41  define passages to the connector  36 ,  37  for IDE data and power supply, respectively, on the printed circuit board  35 .  
         [0038]     Guide grooves  42  are formed on the outer enclosure  38   a.  The guide grooves  42  are designed to extend along parallel straight lines from the rear end of the HDD  17  to the front end of the HDD  17 . When the HDD  17  is inserted into the enclosure  16  through the opening  18 , the guide rails  33 ,  33  of the HDD mounting bay  27  are received in the corresponding guide grooves  42 ,  42 , respectively. The guide rails  33 ,  33  serve to lead the insertion and removal of the HDD  17  in the HDD mounting bay  27  in this manner. When the rear end of the HDD  17  reaches the bottom of the HDD mounting bay  27 , the connectors  36 ,  37  on the HDD  17  are coupled with the corresponding connectors  29 ,  31  on the HDD mounting bay  27 , respectively. A transmission channel is thus established between the connectors  36 ,  29  for IDE data. A channel for electric current is thus established between the connectors  37 ,  31  for power supply. It should be noted that any other guide mechanism may be utilized in place of the combination of the guide grooves  42  and the guide rails  33 .  
         [0039]     As shown in  FIG. 4 , the inner enclosure  34  of the HDD  17  includes a box-shaped enclosure body  43  defining an inner space in the form of a flat rectangular parallelepiped, for example. At least one hard disk  44  is placed within the inner space. The hard disk  44  is mounted on the drive shaft of a spindle motor  45 . The spindle motor  45  is allowed to drive the hard disk  44  for rotation at a rotation speed such as 7,200 rpm, 10,000 rpm, or the like. A cover, not shown, is coupled to the enclosure body  43  for airtightly closing the inner space of the enclosure body  43 .  
         [0040]     A carriage  47  is also placed within the inner space. The carriage  47  is designed to swing around a vertical support shaft  46 . The carriage  47  includes a rigid swinging arm  48  extending from the support shaft  46  in the horizontal direction. An elastic suspension  49  is attached to the front end of the swinging arm  38  so as to extend forward from the swinging arm  48 . As conventionally known, a flying head slider  51  is cantilevered at the front end of the elastic suspension  49 . A so-called gimbal spring, not shown, may be utilized to support the flying head slider  51  on the elastic suspension  49 . The flying head slider  51  is allowed to receive an urging force from the elastic suspension  49  toward the surface of the hard disk  44 . When the hard disk  44  rotates, airflow is generated along the surface of the rotating hard disk  44 . The airflow serves to generate a lift on the flying head slider  51 . The generated lift is balanced with the urging force from the elastic suspension  49 . The flying head slider  51  is thus allowed to keep flying above the surface of the rotating hard disk  44  at a higher stability based on the aforementioned balance.  
         [0041]     When the carriage  47  swings around the support shaft  46  during the flight of the flying head slider  51 , the flying head slider  51  is allowed to move across the surface of the hard disk  44  along the radial direction of the hard disk  44 . This radial movement realizes alignment of the flying head slider  51  above a target recording track on the hard disk  44 . An actuator  52  such as a voice coil motor (VCM) may be employed to drive the carriage  47  for the swinging movement. As conventionally known, in the case where two or more hard disks  44  are placed within the enclosure body  43 , a pair of the elastic suspensions  49  are related to a single swinging arm  48  between the adjacent hard disks  44 .  
         [0042]     As shown in  FIG. 5 , a system controller or chip set is connected to the CPU  26  on the motherboard  25 . The chip set includes a north bridge  54  and a south bridge  56 . The north bridge  54  is connected to the CPU  26  through a system bus  53 . The south bridge  56  is connected to the north bridge  54  through a PCI bus  55 .  
         [0043]     A main memory  57  is connected to the north bridge  54 . The CPU  26  reads out the OS and application software programs, temporarily stored in the main memory  57 , based on the function of the north bridge  54 . A memory module such as a synchronous DRAM (SDRAM), a Rambus DRAM (RDRAM), or the like, may be employed as the main memory  57 . The memory module may removably be mounted on a DIMM connector stationarily mounted on the motherboard  25 , for example.  
         [0044]     A video board  58  is also connected to the north bridge  54 , for example. The aforementioned display device  12  is connected to the video board  58 . The video board  58  serves to supply the display device  12  with image signals based on the instructions from the CPU  26 . The video board  58  may removably be mounted on a specific connector stationarily mounted on the motherboard  25 , for example.  
         [0045]     A network chip  59  is also connected to the north bridge  54  through the PCI bus. The network chip  59  serves to connect the CPU  26  in the computer  15  to a CPU, not shown, in other computer. The CPU  26  is allowed to exchange signals with other CPU through a LAN (local area network), the Internet, and the like. The network chip  59  may stationarily be mounted on the motherboard  25 , for example.  
         [0046]     An IDE interface circuit  61  is connected to the south bridge  56 . The IDE interface circuit  61  includes a primary interface channel  62  and a secondary interface channel  63 . Master channels  62   a,    63   a  are established in the interface channels  62 ,  63 , respectively. The master channels  62   a    63   a  have priority on receiving connection of a primary mass storage. Slave channels  62   b,    63   b  are also established in the interface channels  62 ,  63 , respectively. The slave channels  62   b,    63   b  are serially connected to the corresponding master channels  62   a,    63   a.  The slave channels  62   b,    63   b  are utilized to receive connection of a secondary mass storage. The aforementioned connector  29  is connected to the master channel  62   a  of the primary interface channel  62 . The IDE interface circuit  61  serves to transfer data and/or software programs, stored in the hard disk  44  in the HDD  17 , to the CPU  26  and/or the main memory  57 , for example. The aforementioned CD-ROM drive  21  is connected to the master channel  63   a  of the secondary interface channel  63  through a specific connector, not shown. The IDE interface circuit  61  serves to transfer data and/or software programs, stored in the CD-ROM medium  23 , to the CPU  26 , the main memory  57  and/or the HDD  17 , for example. The IDE interface circuit  61  may stationarily be mounted on the motherboard  25 , for example. Alternatively, the IDE interface circuit  61  may be formed directly on a separate IDE board.  
         [0047]     An ultra input/output (I/O) unit  65  is also connected to the south bridge  56  through an ISA bus  64 . The aforementioned keyboard  13 , mouse  14  and FDD  19  are connected to the ultra I/O unit  65  through a specific connector. The ultra I/O unit  65  serves to transfer data, input from the keyboard  13  and/or mouse  14 , to the CPU  26  and the memory  57 , for example. Data and/or software programs in the FD  22  can be transferred to the CPU  26 , the main memory  57 , and the HDD  17  with the assistance of the ultra I/O unit  65 , for example.  
         [0048]     A BIOS-ROM (read only memory)  66  is connected to the ultra I/O unit  65 . The BIOS-ROM  66  contains a primary identification data  67  and a booting program  68 . The primary identification data is designed to specify a primary identifier for authentication. The CPU  26  first executes the booting program when the computer system  11  is to be started. The primary identifier will be described later in detail. Here, a basic input/output system (BIOS) program should be included in the concept of the “booting program.” A mask ROM, a flash ROM, or the like may be utilized as the BIOS-ROM  66 , for example. The BIOS-ROM  66  may stationarily be mounted on the motherboard  25 , for example.  
         [0049]     As shown in  FIG. 6 , a secondary identifier record  72  is defined on the hard disk  44  of the HDD  17 . The secondary identifier record  72  includes a recording area for secondary identification data. The secondary identification data specifies the secondary identifier for authentication. The secondary identifier will be described later in detail. Numbered data recording areas are established within the secondary identifier record  72 . The individual data recording areas are respectively filled in with a secondary identification data in the numbered sequence. A predetermined identifier is described in the data recording area subsequent to the data recording area or areas filled with the secondary identification data, in place of a secondary identification data, so as to indicate the last secondary identification data filled in the data recording area or areas.  
         [0050]     A master boot record (MBR)  73  is defined in the hard disk  44  subsequent to the secondary identifier record  72 . A master initial program loader (IPL) is stored in the MBR  73 . A boot sector  74  is defined in the hard disk  44  subsequent to the MBR  73 . The IPL is stored in the boot sector  74 . Otherwise, the hard disk  44  further holds software programs such as the OS  75 , application softwares  76 ,  77 , and data utilized in the execution of the software programs.  
         [0051]     Now, assume that the computer system  11  is to be booted. The display device  12  and peripheral devices are first turned on. When the computer  15  is thereafter turned on, a booting program or BIOS program is read out of the BIOS-ROM  66 . The CPU  26  executes the processing in accordance with the description of the BIOS program.  
         [0052]     As shown in the flowchart of  FIG. 7 , the CPU  26  starts a system check at step S 1 . The main memory  57  is checked during the system check. Also, initialization of the peripheral devices such as the display device  12 , the HDD  17 , the FDD  19 , the CD-ROM drive  21 , and the like, is executed during the system check. The CPU  26  judges during the system check whether or not the computer  15  faces abnormal conditions at step S 2 . If the CPU  26  finds out failure in the main memory  57 , or failure or disconnection of the peripheral devices  12 ,  17 ,  19 ,  21 , for example, the CPU  26  forcibly discontinues the processing at step S 3 . The computer  15  is thus shut down.  
         [0053]     As long as the CPU  26  keeps confirming the normal operation of the computer system  11  at step S 2 , the system check keeps going. The CPU  26  judges during the system check whether or not the setting processing of the BIOS should be established at step S 4 . The judgment may be conducted based on the manipulation of a key in the keyboard  13 , for example. When the operator manipulates a predetermined function key in the keyboard  13 , for example, the processing of the CPU  26  proceeds to step S 5 . The CPU  26  operates to provide the operator with a user interface for setting the BIOS. When the setting of the BIOS has been completed, the processing of the CPU  26  returns to the system check.  
         [0054]     The CPU  26  judges whether or not the system check has been completed at step S 6 . If the system check has been completed, the processing of the CPU  26  proceeds to step S 7 . The CPU  26  searches for the boot drive. The CPU  26  operates to start the OS based on the boot drive at step S 8 . The HDD  17  is designated as the first boot drive in the BIOS in this case. The HDD  17  is connected to the master channel  62   a  of the primary interface channel  62  in the IDE interface circuit  61  as described above. The HDD  17  is the sole boot drive among the mass storages in the BIOS. Accordingly, unless the HDD  17  is set in the HDD mounting bay  27 , the OS cannot be booted.  
         [0055]     As shown in the flowchart of  FIG. 8 , the CPU  26  first reads out the primary identification data from the BIOS-ROM  66 , at step T 1 , in the booting process of the OS. The CPU  26  accesses the boot drive, namely the HDD  17 , at step T 2 . The CPU  26  then reads out a secondary identification data from the secondary identifier record  72  in the hard disk  44 . The CPU  26  compares the primary identifier specified in the primary identification data and the secondary identifier specified in the secondary identification data at step T 3 . If a predetermined relevance is confirmed in accordance with a predetermined rule in the comparison, the CPU  26  authenticates the secondary identifier. For example, when the secondary identifier is identical to the primary identifier, the processing of the CPU  26  proceeds to step T 4 . A sequence of binary signals in the amount of approximately 1 byte may be utilized as the primary and secondary identifiers for authentication, for example.  
         [0056]     The CPU  26  then reads out the mater IPL from the MBR  73  in the hard disk  44 . The master IPL takes over the processing of the CPU  26  from the BIOS program. The CPU  26  executes the processing in accordance with the description of the master IPL at step T 5 . The CPU  26  thus reads out the IPL from the boot sector  74  in the hard disk  44 . The IPL takes over the processing of the CPU  26  from the master IPL. The CPU  26  thus executes the processing in accordance with the description of the IPL at step T 6 . The CPU  26  reads out the unique first file of the OS. The CPU  26  thereafter reads out the subsequent program files of the OS. The OS has booted up at step T 6 .  
         [0057]     If the secondary identifier discords with the primary identifier at step T 3 , the processing of the CPU  26  proceeds to step T 7 . The CPU  26  accesses again the secondary identifier record  72  in the hard disk  44 . The CPU  26  judges whether or not there is another secondary identifier. Specifically, the CPU  26  checks whether or not the data recording area of the secondary identifier record  72 , which the CPU  26  is accessing, holds the identifier indicating the last secondary identification data. If the CPU  26  detects another secondary identifier at step T 7 , the processing of the CPU  26  returns to step T 2 . The CPU  26  reads out the secondary identification data from the secondary identifier record  72  on the hard disk  44 . Unless the CPU  26  confirms that the secondary identifier conforms to the primary identifier at step T 3 , the processing of steps T 2 , T 3  and T 7  is repeated.  
         [0058]     On the other hand, when the identifier indicating the last secondary identifier is found at step T 7 , the CPU  26  confirms that no other second identifier exists in the secondary identifier record  72 . The CPU  26  operates to forcibly shut down the computer  15 . The computer  15  is thus turned off. In this manner, unless the secondary identifier specific to the primary identifier unique to the computer  15  is found in the secondary identifier record  72  on the hard disk  44  in the computer  15 , the OS cannot be allowed to boot up. A specific combination of the computer  15  and the HDD  17  should be established to boot the OS. The accessibility can in this manner be limited for the hard disk  44 . The credibility of the security can be improved in the HDD  17 .  
         [0059]     Here, a brief description will be made on preparation of a secondary HDD  17  managing the booting of the OS in the aforementioned computer system  11 . The aforementioned secondary identifier record  72  should be defined on the hard disk  44  in the secondary HDD  17 . Also, a predetermined OS should be stored in the hard disk  44  in the secondary HDD  17 . The secondary identification data specifying the secondary identifier equal to the primary identifier in the BIOS-ROM  66  is written into the hard disk  44  of the secondary HDD  17  in the following manner. The BIOS program is utilized to realize the writing of the identifier. As is apparent from the flowchart of  FIG. 7 , the processing of the CPU  26  proceeds to step S 5  after the start of the system check at step S 1  when the computer  15  has been turned on.  
         [0060]     As shown in the flowchart of  FIG. 9 , the CPU  26  allows the display device  12  to display a BIOS setup menu on the screen at step V 1 . A predetermined option is included in the menu so as to suggest the operator establishment of the secondary identifier, for example. When the CPU  26  confirms the choice of the predetermined option at step V 2 , the CPU  26  reads out the primary and secondary identification data at steps V 3 , V 4  in the aforementioned manner. The CPU  26  then compares the primary and secondary identifier with each other at step V 5  in the aforementioned manner.  
         [0061]     If the secondary identifier discords with the primary identifier at step V 5 , the processing of the CPU  26  proceeds to step V 6 . The CPU  26  judges whether or not there is another secondary identifier. If the CPU  26  finds another secondary identifier, the processing of the CPU  26  returns to step V 4 . The CPU  26  then reads out the secondary identification data from the secondary identifier record  72  on the hard disk  44 . Unless the CPU  26  confirms that the secondary identifier conforms to the primary identifier at step V 5 , the CPU  26  keeps reading out another secondary identification data.  
         [0062]     If all the secondary identifier is not valid at step V 6 , the CPU  26  operates to forcibly shut down the computer  15  at step V 7 . The computer  15  is thus turned off. In this manner, unless the secondary identifier specific to the primary identifier unique to the computer  15  is found in the secondary identifier record  72  on the hard disk  44  in the computer  15 , the writing of the secondary identifier cannot be achieved for the secondary HDD  17 . A specific combination of the computer  15  and the HDD  17  should be established to prepare the HDD  17  capable of managing the booting of the OS. The accessibility can in this manner be limited for the hard disk  44  in the secondary HDD  17 .  
         [0063]     If the secondary identifier conforms to the primary identifier at step V 5 , the CPU  26  instructs the operator to replace the HDD  17  with the secondary HDD at step V 8 . The instructions may be displayed on the screen of the display device  12 , for example. After the operator has pulled out the primary HDD  17  out of the opening  18 , the operator inserts another HDD, namely the secondary HDD  17 , into the HDD mounting bay  27  through the opening  18 .  
         [0064]     When the secondary HDD has been inserted into the HDD mounting bay  27 , the CPU  26  reads out the primary identification data from the BIOS-ROM  66  at step V 9 . The CPU  26  operates to write the primary identifier, specified in the primary identification data, into the secondary identifier record  72  on the hard disk  44  in the secondary HDD. The secondary identification data can in this manner established in the secondary identifier record  72  in the hard disk  44  in the secondary HDD. The new secondary identification data may be written over the identifier indicating the last secondary identification data. In this case, the data recording area subsequent to the overwritten data recording area may be subjected to the writing of the identifier indicating the last secondary identification. As is apparent from the flowchart of  FIG. 7 , the processing of the CPU  26  thereafter returns to the system check.  
         [0065]     The HDD  17  can easily be removed from the enclosure of the computer  15  in the aforementioned computer system  11 . Since the HDD  17  is smaller than the computer  15 , the user is allowed to easily tote the HDD  17  at hand. As long as the aforementioned computer  15  is established based on the combination with the HDD  17 , the user can enjoy the accustomed identical or common operating condition on the different computers  15 . Moreover, the establishment of the aforementioned computer system  11  serves to avoid reduction in the size of the display device  12  and the keyboard  13 . The superior maneuverability can be obtained.  
         [0066]     The aforementioned computer  15  and HDD  17  may restrict the accessibility to the primary identification data in the BIOS-ROM  66  and the secondary identification data in the secondary identifier record  72 , respectively. Only the BIOS program should be allowed to have the accessibility to the primary and secondary identification data. The restricted accessibility leads to a higher credibility of the security. In particular, the overwriting is prohibited on the primary identification data, so that the primary identifier for authentication in the BIOS-ROM  66  cannot be replaced with other secondary identifier in the HDD  17 . A further restriction can be achieved to boot the OS based on the readout from the HDD  17 . Additionally, the primary and/or secondary identifiers may be stored in the BIOS-ROM  66  and hard disk  44  after encryption.  
         [0067]     In addition to the aforementioned computer  15 , a television, a refrigerator, a video reproduction and/or recordation system, a washing machine, and other types of electric apparatuses, may be included in the information processing apparatus.