Heh, you want to disable the NVIDIA on your ASUS laptop and use your HD 4000, whereas I wish I could use my NVIDIA instead of my HD 3000 on my ASUS N55SL...
I took a look at the BIOS file for your laptop. The Primary Display setting doesn't show "SG" (Switchable Graphics), so you could only have one card active at a time (and this is assuming that your laptop display even works when the IGP is only enabled; if it's the higher-power NVIDIA card powering your display, I can bet that ASUS won't have bothered wiring your display to the IGP, 'cause who the hell would want to use that over the NVIDIA?!) and due to limitations in unlocking the menu where the options are stored, you would have to keep flashing your BIOS to switch cards.
I tried switching graphics on my N55SL yesterday through two methods. I didn't brick my laptop but nothing showed on the screen. I used VNC and ran WinFlash again to reflash my old BIOS mod so that my old, Optimal BIOS settings would be restored (the emergency BIOS flash procedure from USB would've also have worked in this case). Still, rathore4u had success in switching his N56VZ from Intel/Switchable graphics to the NVIDIA, but that's the only ASUS success story that I know of.
