LAST EDITED ON Jun-01-02 AT 03:49 PM (EST)
Should that 15 Mb not be 15 Gb?
As for some reason a drive could dissapear only when it got corrupted, or when a CD-Rom drive was added or "moved" from its Driveletter.
Also a "Partition Magic" program can couse such dissapearences.
See and set if not in c:\config.sys:
Directly after that, boot into safe mode.
Go to Control panel, Systen, Device manager, and delete ALL double items that are present in the device listing.
Also it could not hurt you to delete items which are surely no (longer) present in your system.
If an item is found twice ore more, Delete ALL of these items.
Restart, and Windows will redetect your hardware and hopefully brings the missing drive back online.
If not, check if you once used some sort of Partition magic program.
Restart that and see if you can "Unhide" your last partition.