Hey I have the same problem. New Gigabyte Gtx 960 G1 Gaming 2gb and the driver crashes instantly. My old 650ti Boosts still run perfectly fine in SLI on my MoBo, and I tried the 960 in a friend´s system. It worked fine there. On the software side: I tried all available Versions of VGA-Bios (F2,F3,F5), all the drivers i could find (347.25 .52 .88 and .90) and even reinstalled Windows. My mainboard is a ASRock Z87 Extreme4, CPU: Xeon 1230v3, PSU: XFX PRO650W, 8Gb Ram and Win 7 64bit.
I don´t know what to do anymore, tried underclocking as well as disabling tdr via tdr-manipulator. Can anyone offer some help?