I am posting this here becuase it is as good a place as any for other people in the future who may be having the same problems with BF3 (battlefield 3) not launching or crashing during the map change on multiplayer. After much tearing out of hair, I discovered that D3D overrider was causing the problem. If I disabled this program, then I got no BF3 headaches. Thing is, that I have always run my PC with Rivatuner & D3D overrider installed. This is because it has always been the one guaranteed method of getting V-sync in games where it wont otherwise work, and have found that the triple buffering feature can add to frame-rates. The fact that all off a sudden, D3D overrider is causing conflicts with BF3 has got me thinking that perhaps there have been 'updates' in the way that games or driver handle gfx card features such as V-sync, triple buffering, which result in conflicts with programs like D3D overrider.