I'm reinstalling Windows for a friend of a friend, and I'm trying to use an Ubuntu LiveCD (8.04) to clear the hard drive first. (I don't have enough blank CDs for a proper backup.) But there are two folders buried in c:\Windows\assembly that refuse to be deleted, despite being empty. The error message is "Error removing file: Operation not supported," but everything else has been deleted without problems.
The computer was pretty badly infected with spyware and viruses, so it's possible that the filesystem might be messed up, but it seems to be otherwise fine.