Dude, right click and properties then hit compatibility.
Select Vista SP2, should solve the problem!
*nods* I knew about that, just wanted to rule out other possibilities before I tried.
I tell you, it's a pain going through the install routine:
* select compatibility options, start installing
* Install rockstar social club app
* register with social club through browser
* continue install - oh, GFWL wants to update.
* let it update, then start the install again
* start up the game, oh need to link rockstar id with GFWL id.
* return to game, start up - oh game detects a patch, updates itself
* patch says rockstar club no longer needed, removes that.
* now start up the game, but need to log in to social club through in-game browser (I realised after that's not necessary)
* finally, finally, start the game
What a hassle.