my cpu performance monitor which is how hard they are workin are stayin at 100%
i have windows 7 and i have a new sony vaio and i have a desktop gadget that tell me how hard my processors are workin and i am in the process of switchin anti virius and they would stay full blast for a hour straight like i was downloading something at all times.
It is likely that you have a rouge task running. Right click on the task bar at the bottom of the screen and select "Start task manager". Select Processes tab, then sort on the CPU field you can then see what is running at 100%. I would then suggest typing the task in google to see what application this is.