The Basics of CPU Work - Windows Task Manager
The first step towards understanding CPU work is to press CTRL-ALT-Delete on your keyboard and then open your Windows Task Manager. This opens a display that monitors your computer's processor utilization, which is detailed on the graph in the CPU Usage section of the Performance tab.
Depending on your processor you may see anywhere between 1 and 12 individual graphs under CPU Usage. Each graph represents an individual processor thread. AMD processors have one thread per processor core, but some Intel processors have a feature called Hyper-threading that offers two threads per processor core.
Sit back for a minute and watch the graph whle your computer is at idle. Also pay attention to the CPU usage bar that is to the left of the graphs. A normal idle computer is typically using less than ten percent of its processing power, although some less powerful machines, like netbooks or computers that are several years old, may be using up to twenty five percent. If Windows Task Manager reflects this level of usage, your computer is doing normal CPU work. Your computer might still seem slow, but it isn't because the processor is under too much strain.
If your processor utilization graph is constantly over 50%, however, something is amiss. There may be a program in the background that is running without your knowledge, or your computer may be doing work that you're not aware of. This isn't always a sign of malware, however.