I did something to my BIOS now my monitor shows "No Signal".

[himikotogaaa]

I remember enabling a few things. Fast boot, windows 8.1 installation or something like that. I don't know what to do, can someone help me solve this problem?

 

[Barty1884]

Clear your CMOS, that'll revert all BIOS changes you made back to default settings.
http://www.tomshardware.com/faq/id-2176429/clear-cmos-works.html

Option 1 is the universal option (removing the battery) as not all boards have a jumper or button.

Wait 10 minutes though, just to be sure, then reinstall the battery.