Abstract: The present invention provides an independent set of processes and data structures that allow data transfer between differently formatted disks of files specified by the user. The processes identify the file format of the disks, retrieve the files in the source file format, store the source files in a common format in memory that allows the directory hierarchy of the disks to be maintained, translates the files to the format of the destination file system disk, creates index information for the destination disk, and stores the files, directories and indexes on the destination disk in the destination file format. The user can then access and modify the files and transfer the modified files back to the foreign disk in the foreign file format using the same transfer processes. The common memory format is a data structure which is a two dimensional list with one dimension maintaining the directory hierarchy of the source disk and the second dimension maintaining the hierarchy of the destination disk.