Start running virus scan and it should jump to OC frequency.
If it will not go over the 4GHz, its not OC'd.
So I tried that using kaspersky, and it didnt do much, I then used Prime95 and it was over 4400 MHZ with a multiplier of 43. I just cant tell if its still overclocked or not.
Also i'm running a intel core i7 2700k