0) Since it didn't work when he put it back, that seems to indicate something else is going on. :-(

1) I assume the new computer doesn't have the [link|http://support.microsoft.com/default.aspx?scid=kb;en-us;303013|48-bit LBA issue]. The problem sounds similar though. You might want to check the registry to see if this is enabled.

2) Are the jumpers right on the drive?

3) There used to be problems with some hard drive brands not getting along with each other. Does the drive work when it's the only drive in the computer?

4) [link|http://www.knopper.net/knoppix-mirrors/index-en.html|Knoppix] might be a useful tool to help diagnose things. But if the MBRWork disk didn't work, then well... :-(

5) Is it a "dynamic disk"? There are differences between basic and dynamic that are outlined [link|http://support.microsoft.com/default.aspx?scid=kb;en-us;309044&sd=tech|here]. I don't know much about them myself.

HTH a bit.

Cheers,
Scott.