While performing some testing on a Windows 7 Professional workstation running a VL build from MSDN found that a feature I needed was missing – the new Multi-Monitor RDP support. After a little research I found that only the Ultimate and Enterprise editions support this feature; which thanks to Windows 7′s Anytime Upgrade feature I assumed this would be no issue.

But, it was an issue.

It turns out that the build of Windows 7 I was using was missing WindowsAnytimeUpgradeUI.exe and the other related files needed to make the Anytime Upgrade work – and copying the files from another box doesn’t work. It seems this build simply can’t be upgraded in this fashion. So I tried a few other tricks, hoping to find something that would work:

• Reactivate Windows with an Ultimate key; fails with an error indicating that a Professional key is required.
• Run Ultimate edition installer from Windows; fails with this error indicating that you can’t perform edition upgrades.

So being stubborn and determined not to re-install Windows to make this feature work, I started looking for other options. Thanks to a hack for upgrading the RC builds to Final, I found what I needed.

I edited the EditionID and ProductName to reflect Ultimate instead of Professional, rebooted, and then ran the Ultimate installer from within Windows. This time the installer ran without issue and after an hour and a couple reboots it was done. This in-place upgrade/repair procedure allows you to jump to a different edition with fairly little pain. A couple of Windows settings needed to be corrected (primarily display related) and Visual Studio 2010 had to be re-installed, though otherwise everything worked just as it did before.

This is the only method for upgrading these Windows 7 builds that I’ve found, the only other option is to re-install Windows from scratch.