That\'s the sound of your CPU frying. You\'re getting into something you sound like you don\'t have the experience to be messing around with. It\'s very easy to damage your CPU when playing with over clocking unless you fully understand what you\'re doing. For one thing, you never make large changes like adding a whole GHz in speed. You do it in small increments, testing after each one to see if the CPU can handle it. Once you reach the point where funny things happen, such as a buzzing noise, you back it off and leave it. Cheers! Capt\'n Skunky KSP Community Manager