Question : Incompatible NTFS?

Have several machines to upgrade.  All were upgraded from Win2K to Vista Business, each of which went off very well (yeah, it was a total reinstall of a new OS and loading the programs fresh, but that's OK) .  Trying to upgrade to 7 gets error that it's unable to install Windows 7 because of an "incompatible NTFS version."  I've tried it on three identical machines with the same error.  If I run the Windows 7 Upgrade Advisor it says that everything's fine and there's no problems.  

If I boot from the CD, there's probably going to be some data or settings losses I really don't want to have to do.  Any suggestions?

Answer : Incompatible NTFS?

Hummm... that's interesting.

Run the following command on one of those PCs, and tell us what it says:

fsutil fsinfo ntfsinfo c:

... in particular, does the version read 3.1?