Originally Posted by DizZz
You should be able to reinstall windows on multiple computers even though it's oem. I've had a copy for just over a year now and have installed it on 7 or 8 separate computers without any problems. I think they just say that so you buy more copies.
Originally Posted by Conin
It does not matter if your Windows is OEM, you can install it several times even on a completely different and new build, as long as you no longer use the former PC. The only thing that could happen is that when trying to activate it automatically via Internet, it will ask you to activate it by phone instead (I think to make sure it is still your original and legitimate copy) and you're good to go. Two of my PC's have OEM Windows versions (Vista Ultimate x64 and 7 Ultimate x64) and have installed and reinstalled Windows on them countless times due to upgrades/changes of hardware with no problem at all.
the difference between oem and retail license is that the oem can only be used on one motherboard only and can not be transfered.
retail can be transfered but can only be installed to one pc at a time.