Hope someone can help here. Running windows xp and the pc is a packard bell with 768 mb, celeron D processor. When I am on line sometimes I hear like a fan whirring up and the task manager is reading CPU usage 100%. This sometimes drops down to 2 or 3% by itself but sometimes stays at 100% and the freezes and I have to end the application. I am fairly computer literate but thats about it. Any thoughts anyone??