Patent ID: 8473941

Claim:
A method comprising: at a host system that is operatively coupled to a portable storage device, performing: receiving a plurality of file system commands issued by an installer application at the host system; hiding a drive identifier associated with a first file system located at a fixed storage memory device of the host system; removing a directory of the first file system from a list of available directories; preventing write access to the first file system during a copy operation, wherein the plurality of file system commands includes a plurality of application programming interface (API) commands, wherein during installation of a portable application to the portable storage device, at least one of the plurality of API commands is selectively intercepted and modified such that the installer application has write access to a second file system but does not have write access to the first file system, and wherein a set of rules is used to determine whether to selectively intercept and modify parameters of the API commands before the API commands are executed with respect to a destination file system; and selectively intercepting and modifying at least one file system command of the plurality of file system commands before the at least one file system command is executed with respect to the destination file system when the destination file system is the first file system, such that access is directed to the second file system located at the portable storage device.