You receive the message below when attempting to launch/play the game:
Please login with administrator privileges and try again
Microsoft released an update back in September 2015, the update in question stops a certain program called secdrv.sys (DRM related software) from running which was used in our legacy Gamespy editions of Total War.
Microsoft have supplied a workaround solution as referenced below;
MS15-097: Description of the security update for the graphics component in Windows: September 8, 2015
As an alternative solution; Rome 1 and Medieval 2 customers can redeem their GameSpy code through STEAM to aqquire a STEAM version of their game (not affected by this Microsoft update);
Activating a Product on Steam