So what I am trying to do is move my laptops hard drive to an older desktop I have to use it instead of my laptop. Laptop is Windows 8.1 and desktop was purchased in 2010 with Windows 7 on it. I did a test swap just hooking up the hard drive with no luck. Started to boot up but didn't go very far, just an underscore flashing on the screen. Was wondering if there is a way to do this without reinstalling windows as I want to keep all the files currently on this hard drive.