Well, before you contact Intel for a motherboard RMA, hold down the Ctrl and the Alt buttons, then hit the Delete button. When Windows Task Manager pops up, click on the Processes tab, and look at all of the processes you have running. Under the CPU column, you'll be able to see what percentage of your processor time is being utized by each process. They should all be at or near 00, except for System Idle Process. If you have anything else utilizing your processor, it can cause that to happen, although it shouldn't be raising, then lowering it, the way you describe.