Originally Posted by BookCat
Until recently I didn't know what OEM meant. I googled it and found a tech site which gave information advising people to steer clear of it as it was often pirated rather than ex-computer-manufacturer's stock.
Ehh, that's BS. OEM just means Original Equipment Manufacture. It is meant for people building computers. True OEM is legit. You get a CD and a genuine CD key. In my 20 something years, i have only seen one instance of pirated being passed off as OEM, and that was back in the early 90s. Just make sure it has the MS seal. If it is bogus, avoid or return. Amazon and eBay have great policies about pirated goods. And if you buy from Amazon itself and not one of resellers listed on Amazon, you're guaranteed to get a legit copy.
The only real difference between OEM and retail is that MS only wants you to install on one computer with OEM. Retail copies allow you to reinstall on a second computer if the first computer no longer has it installed and functioning. Basically, you can keep your same copy if you migrate to a new computer with a retail version.