CUDA on ASUS motherboard

Hi,

I want to run CUDA on my PC with ASUS Geforce GTX 560 TI TOP, ASUS P8Z77 Motherboard and Intel Corei7 3770 CPU. as you may know my CPU has embedded Graphic accelerator and ASUS motherboard provides a technology which is called iGPU. if I enable iGPU in my motherboard, it share graphic processes smartly between CPU accelerator and Nvidia VGA for better power consumption. I had enabled iGPU but when I installed CUDA toolkit on my system in Win7 x64 after some reboots found that iGPU is disabled. I want to know the CUDA toolkit disabled it? because there is some other possibilities. also I want to know iGPU technology is in contrast with CUDA programming and must be disabled during computation or it can identify Nvidia GPU and have nothing to do with ordinary graphic processes in my system so I can use iGPU with CUDA programming simultaneously.

thanks
Alireza