To get the games to work on your desktop you have to create a shortcut of the program file.
(extract the files again if the program/.exe file is missing)
That wasn't the problem, apparently. It seems my PC was being stupid that day. It gets stupid quite often. Games might work well one day, and the next they don't. Sometimes I have to change the in game settings of more graphically advanced games based on how my PC feels at the time. I can't explain it any better than that.