New build, bios glitches, Please help

So I have built a computer,when I first booted it up I tried to go into the bios, but I got a very glitchy screen I reset the computer and tried and, same result. I decided to just load windows and it work fine. Download all the stuff I need and it was great. I then wanted to try and over clock in the bios so I download the latest bios to see wether that would fix it, just a black screen when i tried to boot into bios. Then i shorted the 'reset comos' pins whist the computer was of, nothing, then when it was on still nothing. I took out the CMOS battery and put it back in, now I get the motherboard spash screen and then black, no matter what I try to do.Please help