I don't work at Oxtord Games so I'm not a professional, but try disabling UAC, how? Try this:
1-Press the Windows key on your computer.
2-Type in "User" and you will find the UAC settings, open the first thing that pops up.
3-Pull the "lever" down and press OK, a popup will appear, it's not a virus (it's Windows), press Yes in the next popup and reopen the game.
I hope this works!