What product/version of Win 7 came out that had the same license number for everyone for that SKU of Win 7?
Well, technically speaking, Windows 7 doesn’t have a “License Number”. It has a product activation key, but this is used to activate the operating system initially. If you do not do so, it goes into reduced functionality mode.
I am assuming that you cannot see your Product Key within the OS—I’m not sure it’s even stored in the registry. Otherwise people would browse for it and try to reuse it, change it, and all kinds of horrible outcomes would result.
If you go to the Systems Properties sheet, at the bottom of the details pane, you should see a product ID, which is based on the SKU.