. . . . Purchased movie edit pro 1HD in 2011 . . . windows 10 computer . . . .
Is this Movie Edit Pro (MEP) 17 or an earlier version?
If the program has been previously registered by yourself, then the serial number should be available in your account at magix.com, login in using Account login icon top right of the home page using, the email address and password used to register the software, under My Products you will find the software serial number
If you do not use the email address the program you originally activated the program with, you can still login in with it.
While you may get this version installed and activated, it was not designed to run on Windows 10 which is a very different operating system to the Windows versions the program was 'certified' to run on, and you may have issues running the program.
Known issues are the DVD burner may not be recognised, and if it is recognised, attempting to burn a disc throws errors.