By right and law, oem is indeed bind to the hardware where you purchase with together. But I can tell you that you can installed it on few pcs and get them all activated same time (tested and work for times), but I not encouraging you doing so. Also the oem had an activation period where you can active it online for x numbers of times and after that period you had to call up ms hotline for activation through their online customer support (experience with xp pro oem)