[Mobhack]

sounds like you may have hard disk corruption - either lost clusters or a bad sector.

After removing the files, run your disk scanner to remove any errors (The test for bad sectors takes forever - so run overnight, if selected). Best to run once with "automatically fix file system errors" and then a separate overnight scan with "scan for and attempt recovery of bad sectors" if required.

Also - if you are going to do all this, then you may as well do a defrag of the drive as well.

cheers
Andy