your porb is not "system idle process", that is mearly the amount the of the system that is idle for you to use,the higher it is the more resources you have...

Right click on yur "taskbar" then click on "task manager" at the bottom it should have yur "system idle process" that should be like 99 when your doing nothing to use yur CPU or Memory...

Yur real prob could be a virus or usb related... take a screeny of the task manager process's page and post it,I will look at it and try to diagnose the prob for you if you want...