I have a GeForce 8400 GS and compatible updated driver 341.44 installed on my Windows 8.1 x64 machine. When I tried to install CUDA 7.0 it showed that it could not find compatible hardware but I went along and chose to not install the provided driver and looking at this website Nvidia Installation guide ran deviceQuery after installation but got this output.
CUDA Device Query (Runtime API) version (CUDART static linking)
cudaGetDeviceCount returned 35 -> CUDA driver version is insufficient for CUDA runtime version Result = FAIL
Help me install it properly.