I am noticing this from past 5-6 days, when my CPU utilization comes up to the 65% my desktop starts beeping and the Fan of the desktop sounds it is touching somewhere in the CPU. But i have opened the CPU and checked it but there is nothing like that. Some time the CPU becomes very hot and then the fan runs very slowly and smoothly without any noise. I dont know what is this problem is about and how to solve this problem. Please help me out.