I had this issue after finding out I had a worm attack the registry on my hard drive. I had to put the hard drive in a case and use a program called "kill disk" (free download) to completely wipe the disc. The normal reformatting procedure merely writes over top of whatever is there rather than erase the disc and start new.
try that ...
http://www.killdisk.com/downloadfree.htm
Jason
January 2008