Time Out Limit Error While Realtime Rendering

I am receiving an TO limit error while realtime rendering or creating a final render in blender 2.63 - I've done everything including updating or changing drivers (ive connected Nvidia so ive tried out all the drivers they've supported me with), reinstaling Blender and even reinstalling system, but the error still remains. I am Rendering using GPU rendering Mode which was activated in blender file menu user preferences/system/compute device/CUDA. I don't understand why im getting the error since the Graph card performance is normal I've tested it with Stability Test and and it ran over 110 mins without malfunctioning till i stopped it.

Now Nvidia had suggested me changing the TDR. I've created environment and models based on this image - so there's bunch of stuff in it. I am Running Win32, 7 ult. 2 gb of RAM, AMD Athlon 64 x2 dual Core Processor 4800 + 2.51 ghz. Now GPU, Gainward 630 GT 2gb (Direct X 11, PhysX, CUDA Support), Ive bought this GPU Couple of weeks ago specially for GPU Rendering since my x card had lower shader. I am getting Error only with Blender (I've tried rendering on 2.61, but getting same error), it works fine with games (I have 3 games installed all on max Graphics, and they work fine).