The biggest change is the absence of a product key, which was included on the holographic Certificate of Authenticity (COA) sticker with PCs that came pre-installed with Windows 7 or earlier versions.

I have a CoA on a laptop with a serial key, but the version of Windows has rubbed off. I know it's an OEM version of either Windows XP or Windows Vista. How can I determine which of the two it is ...

Last week we told you about a complaint from indie trade association ITACS that some of its members were having trouble reinstalling Windows for customers on whose PCs the COA sticker has either ...