I am new to OC'ing having just built a rig with an Asus P8Z77-V mobo and an i7 3770k cpu. I had previously overclocked on TurboV EVO to what prime95 deemed stable at 4.5 GHz with a cpu voltage of 1.240 (Vcore of 1.3V under stress test). Stupidly I decided to try an auto tune to extreme on TurboV EVO to see what it did. It crashed the system badly and forced me into the BIOS where it had made unknown saves to it. I am now getting 4.3GHz at cpu voltage 1.285 which was much worse than my own overclock.
I too have now tried changing the voltage in BIOS to no avail. Please let me know if there is a fix to this and whether I should reset the BIOS to its original state and how best to do this.