This is perfect for the DYI building a home PC and the gamer community building the ultimate gaming PC.
You will use the Windows install seed from Microsoft as always, insuring you have the latest version. There was a link in the instructions. The Groupon supplied a license code that you use to activate Windows on that PC. If you remember the little green stickers with XP or Win 7 code that used to be on the PC case, this is the equivalent code. Great instructions are provided.
