Can't install the patch

[Castellon]

Sounds like you have no registry entry for your game.

Manually uninstal the game following the procedure outlined in the sticky thread on the topic.

Then install, then apply patch.

 

[Castellon]

Also I did not ask if you had the On demand version, cause that is patched already.

 

[Castellon]

Always suggest to do fresh install and latest patch.
Please see support forum rules as well, they are in the sticky thread named "You must read this before posting"