So my friend just got a laptop off another one of his friends but it had everything installed on it still. So he wiped the hd and installed a fresh copy of windows. The windows was only SP1 and is a real copy of windows. For some reason when he installs service pack 2, the installation freezes on "Checking Product Key." He doesnt know much about PCs since this is his first and hes only worked with MACs and i've never had this problem before. Please help!