OK,
Have you tried repartitioning the drive yet? Another suggestion would be to get a new drive, strap it as "Master" and the old drive as the "Slave". This will get you lots of new storage, but of course it will hit you in the pocket to do so. I should have stated this before, but your problem doesn't sound like the mother board. Autoclave is supposed to be a good program, but I don't recall it as having the ability to do a low level format that would include the proprietary sectors where the FAT's etc. are stored.
L