Account/Library/Click on game all downloads/patches there. How did you manage to download the game without seeing the patches who are in the exact same place?
Are you sure its in there?
It says Patch 1.05 but next to it says 1.04 to 1.05
Also it says that that patch is only 96 MG
isn't 1.05 almost a gig?
Only on Steam ;)
Gog patches are much smaller (for the same content - Steam needs to download all new files, whereas gog updates existing files with a patch).
If you haven't got at least 1.03, you'll need to download the main game installers (currently updated to 1.05)
In 'My Account' you should see three patches (1.03 to 1.03.503 , 1.03 to 1.04 and 1.04 to 1.05) but if you've an earlier version (ie you downloaded it at launch and haven't patched it since) then you'll need to redownload the whole game.