After imaging a Windows 7 machine so as to clone to multiple others I came across a slight hassle: how to change the product key on the newly cloned PC? Previously under XP I would have used a key changer tool such as WinKeyFinder but I had thought that the "Change Product Key" option in System Properties would do the trick in Windows 7. Unfortunately the "Change Product Key" link wasn't showing in System Properties. Perhaps this is because this was an OEM version of Windows 7? I'm not sure. But here's how to do it: Open a Command Prompt Type "slmgr.vbs -ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx" where the xxxxx characters are your product key. Give it a minute and you should get a message saying that the product key has been updated. Then type "slmgr.vbs -ato" to active Windows with this new product key. You should then get a message saying that Windows has been successfully activate. Hope this helps.