[GT2000]

I would say the odds of all drives being bad are pretty big, unless of course there's something else going on causing the drives to eat it. So you said you tried the hdd with the "bad" install in a different computer.. and the same results? Did you try installing windows on the drive from a different computer and then transplanting it back to the original system? The only really possible thing that comes to mind right now would be, memory, bad ram likes to corrupt data.