If it is not an OEM version, use the phone method to activate and talk to areal person.The phone number should be displayed during the activation process."Z-Tech Enterprises" wrotein message news:CBD7132F-6B21-426C-B08D-D29A946C606F@microsoft.com...i put windows vista on one of my laptops but a tookit off and went back toxp but then i installed itt on another laptop and it said the product key was already in use and i bought home premium at best buy   read more »