I have an i5 2500k Sandy Bridge edition @ 3.3GHz. I went into my BIOS and set the CPU speed to 4400MHz and then saved it. But when I go on control panel and then into system it doesn't actually say 4.4GHz it just says 3.3Ghz?
download cpuz and run a program that stress your cpu(ie prime95) and it l show u the clock speed.
Win does control panel usually displays the stock speeds some times, mine did it for a while and now it shows my oc speed, could just be a small glitch, so yeah like above try a program like cpuz