Windows 7: Switching from Ultimate to Professional without reinstalling ?

tesseract4d · 08 Sep 2010

I am using a Windows 7 Ultimate and I want to switch to Professional.
Is it possible to do this without having to reinstall windows again - ie format my C drive and then install Professional to it.
The obvious concern is that I would have to reinstall all software and that would be too much of a bother.

What is the best way to do this ?

And just fyi, I've also dual booted my machine with Fedora as well.

richc46 · 09 Sep 2010

To the best of my knowledge the only way to downgrade from Ultimate to Profesional is to reinstall.

A clean install would be the best way.

Darician · 09 Sep 2010

There's no way to do that. You can only upgrade to higher editions. If you're at Ultimate, then if you want to go to a lower SKU, you will need to do a reinstall.

gregrocker · 09 Sep 2010

You can change between retail versions with the popular workaround many beta testers used to change from the RC to a retail version.

Change the two registry keys shown below to Professional exactly as they are typed, which tricks the installer into thinking it is doing a Repair Install which is always allowed:

Switching from Ultimate to Professional without reinstalling ?-regkeys.png

(click on image to enlarge)

Next run the Professional Installer from desktop, select "Keep Connected To Internet" to get latest drivers and updates into Installer, then "Upgrade". You will have to reactivate afterwards with the Professional Key, but activation is reset anyway in a Repair Install.

I tested this about two weeks ago successfully from Ult>Pro after reports it wasn't working. Another Guru also found it to work then.

The performance reported by many who tried it after Windows 7 release are the best reports ever on in-place Upgrade, completely contradicting MS claims that beta code couldn't be upgraded. Two friends of mine who I did the RC Upgrade to retail for via Remote Desktop don't even want the promised clean install now when I come to visit.

alphanumeric · 09 Sep 2010

I've gone from Home Premium to Ultimate and then back to Home Premium "without re-installing" using the work around Gregrocker posted above.

richc46 · 09 Sep 2010

Quote: Originally Posted by gregrocker

You can change between retail versions using the popular workaround by which many beta testers changed from the RC to a retail version.

Change the two registry keys shown below to Professional exactly as they are typed, which tricks the installer into thinking it is doing a Repair Install which is always allowed:

Attachment 96355 (click on image to enlarge)

Next run the Professional Installer from desktop, select "Keep Connected To Internet" to get latest drivers and updates into Installer, then "Upgrade". You will have to reactivate afterwards with the Professional Key, but activation is reset anyway in a Repair Install.

I tested this about two weeks ago successfully from Ult>Pro after reports it wasn't working. Another Guru also found it to work then.

The performance reported by many who tried it after Windows 7 release are the best reports ever on in-place Upgrade, completely contradicting MS claims that beta code couldn't be upgraded. Two friends of mine who I did the RC Upgrade to retail for via Remote Desktop don't even want the promised clean install now when I come to visit.

Excellent, I would give rep for this, if I did not already. Great going Greg. You taught me too.

ishikawa01 · 14 Sep 2010

Can I also switch from Home Premium to Professional that way, or can I do it like an "upgrade"?

pparks1 · 14 Sep 2010

Out of curiosity, what is the reason for wanting to downgrade?

alphanumeric · 14 Sep 2010

Quote: Originally Posted by pparks1

Out of curiosity, what is the reason for wanting to downgrade?

In my case after doing an anytime upgrade to Ultimate (with an E-Bay key

). I had to go back to my legal Home Premium and didn't want to re-install. Anytime upgrade just unlocked the extra features so I used the workaround to disable them again. All my installed programs remained intact and I didn't have to reload all my music, pictures and documents. It saved me from having to redo everything from scratch.

alphanumeric · 15 Sep 2010

Quote: Originally Posted by ishikawa01

Can I also switch from Home Premium to Professional that way, or can I do it like an "upgrade"?

There is really no need to do it if you are going up a version. Windows 7 is coded to let you go up in version with anytime upgrade. Just launch anytime upgrade and type in the product code for your Professional version. If its a valid code you will be upgraded to Pro and unlock the extra features of Pro. You may have to activate again but if its a legal code/version that shouldn't be a problem. Windows 7 just won't let you go back. It won't let you downgrade in versions unless you do the reg edit posted above and trick it into thinking you have a lower version.

Windows 7: Switching from Ultimate to Professional without reinstalling ?

Switching from Ultimate to Professional without reinstalling ? problems?