If you have a pirated version it won't recognize the .exe
Owned.
Actually, there is an issue with the drivers that does not allow them to detect installed apps.
There are two solutions for this:
1, It can be worked around by creating a shortcut to TESV.exe on the desktop.
2, If you uncheck the 'show only programs installed on my computer' in the nVidia control panel, select Skyrim and make the settings, they get applied fine when you launch the game.
Oh, and AO even works with the LAA launcher.

I for one however don't really like the result, as you can see the AO shadows even when the objects themselves are obscured by fog, like in mines or underwater... highly unrealistic. Better to stick with tree and land self-shadow setting.