I'm working on an HP desktop running XP sp3. The mobo, and other components, were changed out and now it is not recognized as an HP OEM machine and can't be activated. The owner used a an activation and WGA hack and was able to use the machine for a couple months until MS caught up with it and now it won't get beyond the login screen without activation. I do have a copy of XP I used on one other machine that's not being used anymore and thought maybe I could transfer it. I'd like to simply change the product key, without reinstalling, but can't get past the Activation lock out. If I can get in and manipulate the registry I could change the key. I can get in with a Hiren's boot disk, but I'm not sure what path the get to the registry. Any thoughts?