My cousin's daughter bought a copy of Win 7 on eBay last winter and got locked out a month or so ago with the sweep MS did for illegal keys. She is in school now and bought Academic Win 7 Pro and tried to input the key but Windows would not take it. Does she have to do a full install to use the key? She has a lot of stuff installed and does not want to start from scratch. Any option to get the legal Academic key to work with existing install?