(Help) Disabled the monitor

So i made the most stupid mistake ever. I'm a Nvidia user. I wanted to play Sonic Generations at full speed and it didn't notice my Nvidia card. I found how to fix it. I clicked Screen Resolution and made another screen that uses Nvidia. The game worked faster but because of my silliness, I selected the Nvidia screen as the main screen and now it's all black. I tried safe mode but even if I tap F8 it still doesn't work -it may be because i can't see anything so i tap it at the wrong time but i don't know-

Can somebody help me? And sorry for my bad English. :/

Oh, I forgot to say it. I'm using a laptop. :/

I finally can use the safe mode but can't use the Internet or when I open dxdiag, my graphic card cannot be found. What should I do? Help me, please. :|