I bought a refirb laptop from Newegg and after about 6 months I started getting a message saying "This copy of Windows is not genuine". This message comes up every 15 minutes or so and I just keep clicking on the 'later' button. I have another couple refirb boxes which came with Windows Vista installed but I installed Linux over it. There are stickers on the side with the 25-char product key on it. I'm wondering if I could use that product key to install on my refirb laptop that keeps nagging me about an invalid copy of Windows.