Microsoft reports there is no direct upgrade path to 7 Ultimate from a non-like version. Unfortunately, you will need to do a clean install. For some reason, this is only with Ultimate.
Other cases where a clean install is necessary:
- Going from a greater version to a lesser version of 7.
- Going from x86 to x64 or the other way around.
Its my understanding that Windows 7 Ultimate is so different from Vista Ultimate that a clean install is necessary. I attempted to do an upgrade from Vista Ultimate to 7 Ultimate and it forced me to do a clean install with my files being placed in a directory named windows.old. I tried it so often I had a windows.old.004! That was a nightmare! Good luck.
-J
MCP, MCSA, MCSE, VCP.