Windows 7 Downgrade

[jamesharding]

Hello, World!

I have a quick question regarding my choices...

I have my self-build desktop computer with me at University, recently was unable to boot into Windows for some unknown reason. Needing the computer for work, I backed up all of my files using Hiren's BootCD and then wiped the disk clean to reinstall.

I bought a retail copy of W7 Home Premium, which I had been using on the computer, but those disks are at home I borrowed a W7 Professional disk from a friend, and installed that, seeing as I need the computer for exams...but it obviously won't let me use my Home Premium keys. In a pinch, this is fine because it will let me get my work done until I get my own disks from home over the Christmas break...

I was wondering if there was any possible way to, without doing yet another clean reinstallation, disable the "professional" features by downgrading to Home Premium. I know that it is a stretch, but I am sure that there is a way to do it.

Cheers,
James

 

[ignatzatsonic]

There is some discussion of it here, I haven't read it and can't vouch for accuracy:

Downgrading Win7 Pro to Home Premium - general-discussion - windows-7

 

[gregrocker]

You can achieve this using the popular workaround by which many beta testers in-place upgraded from the RC to any retail version of Win7. By changing these two registry keys it fools the Win7 installer into thinking it is doing an always-allowed same-version http://www.sevenforums.com/tutorials/3413-repair-install.html?ltr=R.

In your case you would change the keys to read exactly HOMEPREMIUM for the EditionID, and Windows 7 HOMEPREMIUM for the ProductName. Back up your files and set a SysRestore point first, type Regedit in Start Search box.



Then run the Win7 Premium Installer from the desktop choosing Upgrade install. Install your Product Key afterwards at Computer>properties activation link.

You can unlock all versions in the Pro installer by extracting the ISO using ImgBurn then running this tool on it before burning an all-versions DVD: Ei.cfg Removal Utility Lets You Use Any Product Key With Your Windows 7 Disc

Or for the purpose of doing the Repair Install workaround you can simply extract the ISO's files to your computer, delete the ei.cfg file in Sources, then run Setup as Admin to start the Repair Install, choosing your licensed version.

 

[jamesharding]

Thanks!

Just out of interest, does doing one of these repair installations leave crap all over the place within the computer? Will it "slow down" my computer doing an in-place upgrade?

 

[gregrocker]

It depends on what condition the upgraded OS is in. If you have a new Pro installation you're happy with, then it should be fine.

An in-place Upgrade keeps all programs, files and settings in place while reinstalling the OS. It can go wrong if there are corrupt settings imported into the new OS.

If you have hesitation about in-place downgrading from the Pro install, then clean reinstall your Home Premium after wiping the HD to get the cleanest possible slate.

Here are some tips for getting a perfect clean reinstall: http://www.sevenforums.com/installation-setup/125874-re-install-windows-7-a.html#post1086729