How do you record ONE game window with msi afterburner?

I am using MSI afterburner to record my game videos. The problem is when I multibox 4x WW barbs in diablo 3, afterburner defaults to recording all 4 screens at the same time. With 4 game videos recording it is a bit too much for my 7970 which is overclocked to 1100MHz/1500MHz. My FPS drops to 20 when there is a lot of action on the screen. Without afterburner running, I can run 4 game clients all at 1920x1080 max settings and maintain 60 FPS while using only 80% GPU power.

I have been unable to figure out how to turn off 3 of the recordings and still keep one going. Any of you figured this out yet?

Thanks