Sounds like the Master Boot Record (MBR) is corrupted. Since it is an XP installation, you could try the Windows recovery console. You stated that the file system is Fat32, so it might be fixable to some extent. Might even be able to use a Windows Millenium or 98SE boot disk and use FDisk switch /fixmbr or /MBR, It's been so long I forgot which. Search the Microsoft site for more information on this. The "Bad Superblock" reference usually points to an issue with the Windows MBR. As stated before by RandomGoon, it might also be a virus. If your partition is over about 32 Gig, it might be Windows XP limitations. It sometimes does not appear to play well with larger Fat32 partitions. It is not able to create/format one larger than 32 Gig, so there might be a reason.