Hello, I have my mother's Toshiba Satellite L50t-A, Part No: PSKLJU, which has Windows 8.1 Core on it. I would like to install Windows 8.1 Pro WMP. When I insert the Win 8.1 Pro WMP, and run the setup on the disk, nothing happens. I don't want to erase any drivers or settings. Can anyone describe to me on how to upgrade with my Win 8.1 Pro WMP? I would really appreciate it very much. Thank You.