Oho, so it wasn't the computer's fault...

On a hunch last night, Lisa tried swapping the spare hard drive into her one working T30. It refused to load, just like the Toughbook. Therefore, it's obviously the drive that's bad, not the Toughbook. This is good, because it means we can consider getting another drive and cloning a working WinXP system into it to run the Toughbook.