Repartiton and reformat? Perhaps

it is an NTFS partition? otherwise (FAT32) use that PowerQuest tool I mentioned in the PM.

You can try to add the disk to an NT4.0 workstation or server, (don't forget to install ATAPI4 (comes with SP4) from microsoft otherwise it cannot see your whole HDD if HDD > 8GB) Perhaps from NT you are able to recover. However it's very unlikely...