Also, a bit of a warning on OEM CDs. OEM, for those who don't know, stands for Original Equipment Manufacturers. It was intended to be sold by Microsoft to resellers such as Dell, Gateway, HP, etc. to come loaded on a CD.
It was easy in the past to purchase these by what even looked like reputable dealers on the net. Microsoft has SERIOUSLY cracked down on these by sneaking their Genuine Authenticity Certificate checkers through your updates. These check the CD code of the OEM OS against what is on their database. The software can find the CD key on your PC and send it back to what they call the mothership. I had this happen to a friend of mine and watched as one feature after another shut down including her CD. This can be done with all sorts of software.
You have three options given the deals the Geoffrey has mentioned. Find the deal and run it by Microsoft. Watch very closely for the update. (but it will get by you eventually). Or purchase the OEM knowingly, contact Microsoft and report the company for selling you bogus software, and Microsoft will probably give you a good key.
Again, this offer may negate all this. Just want to make sure you don't pay for an OEM and get screwed. Generally, if the full version costs about $300, the OEM version will run you about $129 if you search on Nextdeal.
