I'm currently using a laptop purchased in china, running the windows 7 ultimate that came with it. I'm looking to do a fresh reinstall of windows using the same activation key. Does it matter which windows 7 ultimate image/CD I'm using? Can I use one downloaded off microsoft US's site/english language sites and still activate the product with my Chinese product key? Is the product key I have only used for a specific version of windows 7 ultimate?