This is TOTALLY WIZARD
I'm in the process of setting up two machines for a client of mine - both machines identical HP OEM Windows 7 Home Premium boxes, so I set one up soup-to-nuts and then cloned the one drive to the other box.
It worked flawlessly. That is, until I remembered that this thing would probably barf on Genuine Windows, (or the first one would), which would have been a HUGE EMBARRASSMENT for me. . . So, I went to the computer's properties where I figured I'd just change the key - but there's no option there to do this. . . .
If it weren't for your timely advice, I'd probably be so hozed it's not funny.
Of course, I would not be surprised if the actual instal had a generic key that would work on a zillion identical boxes - but I'd rather not take that chance. Especially when the client is a lawyer