I have a 3 year old Alienware PC with a Pentium 4 2.66GHz, 1 gig DDR ram and GeForce 6200 video card. Recently, I noticed that my CPU usage would spike from 0% to about 50% every few seconds like a heartbeat. This occurs even after a restart with no start up programs. I've ran Spybot, Adaware, AVG and have Norton installed. Looking at the process monitor, when the spikes occur every few seconds, the CPU usage jumps from 'System Idle Process' to 'System' then back to the prior. The memory usage, however, stays the same. I have tried rebooting with all start up processes disabled and this still occurs. However when starting the computer in safe mode, this does not occur. Any ideas as to how to make this stop? It makes gaming, music and videos impossible as it causes the entire system to hiccup every 3-5 seconds.