Installed Windows Vista and Computer was running then...

I have an Asrock x58 Extreme motherboard OCZ 1600 DDR3 Ram and i7920 processor. I installed Windows Vista 64 and all the drivers and such. I boot to Bios and go to the EZ OC option to overclock my CPU to 3.6 ghz. I exit and save, computer shuts down immediately. I panic but it turns back on after a 2-3 second delay. My monitor then has no picture and when I reset, it shuts off then turns back on in 2-3 seconds. I did a CMOS reset so the computer turns on normally when reset but there is still no picture although the computer posts. What does this mean?