So, just built two systems here, both Win 7 x64 HP OEM.
I forgot to label which sticker was for which computer. Not that I'll need to re-install anytime soon, but yah, how can I verify which CD I used for which computer now?
The CD's are in their jewel cases associated with the right product keys, no doubt about that... I just mixed up the two cases, so I don't know which product key belongs to which box.