Windows XP Corrupted my File System, Now What?!

Hey guys, I recently re-installed WinXP and I backed up all my data to one drive and removed it. Then, I installed the new OS and put the drive with the backups back into the system. When WinXP booted, I could see only one folder and then all the subfolders had gibberish for names along with the files. So, I booted up Knoppix and found that all the files were fine and still there with the correct names. After this, I booted back into WinXP and it ran a scan on the whole backup drive saying it needed to check that disk. It said there were some errors and they could not be fixed. When WinXP got booted up again, I tried to look at the drive again and found the one file I could open was still named correctly but it was an unknown file extension instead of a folder icon. Fearing the worst, I opened up knoppix again and it cannot read the folder either, it is still an unknown file type as well.

What can I do?! I really need this data since its my bookmarks, email, and other important irreplaceable stuff. Help is greatly appreciated!