Posted 07 January 2010 - 08:59 PM
DON'T use the OEM product key.................................. Use your product key that is on your computer, when reactivating a repair installation Microsoft will tally up your computer spec and licence key, if they do not match Microsoft will not activate your install.
In simple terms a licence key (Unless specified) will only activate one operating system on one computer. Once this is done Microsoft gathers information about this particular pc, E.g Make, model, processer type, processer speed, make, model of processer, memory make, speed , size, so on and so forth. This is nothing less than a finger print.
If you use the product key for the disk you have borrowed Microsoft will immediately know that someone else has used this pruduct key on a different computer to the one you are trying to activate it on. However if you use the product key that is on the sticker on your computer Microsoft will merely think that you have reinstalled the OS with the disk that came with your Pc as the product key will match your computer specs.