Q: Is it legal to buy and install the -- significantly cheaper -- OEM System Builder version of Windows? There is conflicting information all over the web!

A: NO! According to Microsoft's licensing documents, purchasers of the OEM System Builder version can't use it on their home PCs -– they has to use the OEM preinstallation kit (which is part of the System Builder deal), install it on a PC, and actually sell that PC. MS stated this specifically in their . The OEM System Builder version is designed for smaller PC dealers. If you read the fine print on some websites, such as Newegg, this becomes very clear:

Unfortunately, Newegg is one of the very few websites that includes this information. A lot don't. So while you can use it, you're actually running a "non-genuine copy of Windows".

Q: I've lost the Windows DVD or my recovery disc that came with the PC and now my PC just crashed. Can't I just use a different DVD or burn my own and reinstall Windows using my OEM key?

A: You could "borrow" a Windows DVD from your neighbor or download/burn an (Microsoft's online retail partner) and activate Windows with it. It would run for all eternity and have full support for updates. But Microsoft's licensing agreements see this as a violation as you're combining a license from one version with the physical media of another version. Hence: Not legal. You'd be better off trying to ask your PC manufacturer for replacement media.