Win7 licensing question

A couple months ago, my stepson installed a copy of Win7 Professional on his laptop and purchased a product key (against my advice) from one of those "Win7KeyShop" rip-off sites. Of course, two months later the key is now coming up as counterfeit/invalid.

I'm wondering if I can purchase this OEM Version from NewEgg and use that product key to "legitimize" his copy of Windows 7 without having to do a complete re-install. My main concern is that this "OEM" product key might not be valid for the "Retail" version that's currently installed. I'd hate to get the "This product Key is not valid for this version of Windows" error message.

Of course, I can do a full re-install if necessary, but I'd rather not.

Any info or advice will be much appreciated.

thanks,
JohnB

The key you are looking to purchase, will be good.
But it would be best to reinstall to make sure you have NO nasty's from the old disk.

Clean Install Windows 7
SSD / HDD : Optimize for Windows Reinstallation

Providing it is the same version and you trust the ISO source for the original installer, then just change the Product Key at Computer>Properties activation link. If that link is not active, run an Elevated Command Prompt to type slmgr -ipk followed by a space and the new Product Key. SLMgr Commands and Options with Product Key Activation

If you want to buy a lesser or different version there is a workaround to change Win7 without reinstall.

Thanks, theog. Hopefully you're correct and I'll be able to use that key "in-place" without having to re-install. I'll post my results here.

I don't think there should be any residual "nasties" from the original install disk. It was a legitimate Win7 DVD that he borrowed, not an .iso from a downloaded torrent or anything like that.

best,
JohnB

Looks like you are good to go.

I hope so. Maybe next time the kid will listen to what I say instead of wasting $30. Probably not...

Grand Kids are same.