Okay. This is all you should need to do:
Turn off your computer.
Flip the power switch on the Power Supply to off.
Press the power button (it will discharge any electricity still there)
Now, your computer should be off, and there should be no lights on inside it.
Wait for a minute or so, switch the power supply on, and then boot.
if that doesn't work (which it should, according to the manual for your motherboard), then do this:
Turn off your computer.
Flip the power switch on the Power Supply to off.
Press the power button (it will discharge any electricity still there)
Now, your computer should be off, and there should be no lights on inside it.
Next, do the following:
Find the CMOS Jumper:
Turn on the computer (flip the power switch, press the power button)
Press the Delete button, and it will go into the BIOS. Then, set the parameters back to what you want.
Once you're done, turn off the computer, switch the jumper, and turn it on again!