about 1 1/2 weeks after installing an old windows 7 ultimate 64 bit OS disc, when i booted this morning i get a message" windows 7600 not genuine", no i assume i there someway to fix(i no longer have my product to key or original packaging for windows 7)" this but first i want to ask, what will happen i I just leave it be? And Is there a legitimate way to buy solely the product key(I don't have $100+ to spend on a new OS)