I just built an ASUS A88XM-plus with am AMD A10 7850 and loaded a version of windows 7 64 pro I had from a previous computer. I got through the load and entered my KEY and it didn't except it. OK I get it, I need to purchase a new version windows 7 64 bit pro. I updated over 200 updates ect and the computer is working way past my expectations, wow. Don't want redo all I have done.but I will. My question is can I purchase one of the OEM versions available from Amazon or New Egg and just use the keys. I have seen that some guys have had problems with their keys. Do I need to do a complete re install with those disks. Do I need to reformat the disk. Or do I need to go to Windows 8.1 heaven forbid. Any sugestions