So I am running the Steam client version of the game, and while it runs okay and everything, the Steam features are not connecting for me. Steam shows me in-game until I allow the UAC dialogue through and the launcher starts; then it doesn't say I am in-game any more, and the overlay doesn't start (and as such, is not available while in the game). My brother and at least 2 friends (on Steam) don't have this issue, so I don't know what could be causing the overlay not to work for me.
With how often this actually applies, I am not sure if you're actually trying to be helpful or trolling...
Click no on the UAC popup when launching it from steam, then the steam overlay will work. If the game needs to patch then you'll need to click yes for the patcher to work.