Upgrading Windows 7 Home Premium to Ultimate. Can be done.

In case anyone is running into issues trying to upgrade Windows 7 Home Premium to Ultimate, I did the following things and got it to work. I ran into the "Can't upgrade. Need clean install" issue, and the "you have a later version" issue.

1. Changed the two registry keys in

Hkey Local Machine\Software\Microsoft\WindowsNT\CurrentVersion\

Changed

Edition ID to "Enterprise"
Product Name to "Windows 7 Enterprise"


2. Browsed the Windows 7 Ultimate CD directory, found the Setup.exe file, right mouse clicked it, selected "properties", and told 7 that I wanted to run this file in Vista Version 2.

Then ran setup from Windows 7 Home Premium.

Worked great.

You obviously need an upgrade license for this to work, but I had just purchased one.

You could have used AnyTime Upgrade.

No install files needed.
Only the Upgrade key is need.
Anytime upgrade only adds-on the Programs & Features from version to version.
Windows Anytime Upgrade - How to

The workaround you found has been used here many times with success. Only the regedit is needed from the original steps by which many originally changed from beta to RTM: Upgrade the Windows 7 RC to any retail version « Icrontic Tech

If you are one who requested this earlier it was likely not suggested because you are using Enterprise which uses a different activation scheme and thus hasn't been viewed previously as a candidate for the workaround.

I doubt if Anytime Upgrade would work because it's process is started by inserting a key and Enterprise uses VLK which isn't a consumer key. But someone could try it as well.

Thank you for heads-up that the workaround to in-place Upgrade between Win7 versions works to Enterprise.