nvidia and Intel

Hi all,
Thanks for your help, I've read through this forum many, and it helped me a lot. But this time, I don't find the answer and I'm sorry, I need your need.

I have computer with 2 GPU :

lspci -nnk result for the card :

00:02.0 VGA compatible controller [0300]: Intel Corporation 4th Gen Core Processor Integrated Graphics Controller [8086:0416] (rev 06)
Subsystem: ASUSTeK Computer Inc. Device [1043:129d]
Kernel driver in use: i915
Kernel modules: i915


01:00.0 3D controller [0302]: NVIDIA Corporation GK107M [GeForce GT 750M] [10de:0fe4] (rev a1)
Subsystem: ASUSTeK Computer Inc. Device [1043:129d]
Kernel driver in use: nvidia
Kernel modules: nvidiafb, nouveau, nvidia

It was working, on the the Intel card. But I wanted to play flatout 2 on it, and the Intel card was a little bit slow. So I installed the nvidia driver, and then, the Xorg dosn't start. So I remove /etc/X11/xorg.conf, and it start.

But it's not the Intel driver now, and there no 3D acceleration !

How can I go back to the Intel driver ?
And is it possible to install the nvidia driver ? I've tried all the internet ( lol! ) but nothing worked...

Thanks a lot for you help.