A properly functioning computer, at idle, will use hardly any CPU power. When that usage spikes, and there is no apparent reason that a program would be using a large amount of resources, the problem should be troubleshooted with the Task Manager. Once the problematic process has been isolated, it can be terminated, freeing up the available CPU power. It only takes a few minutes to troubleshoot this problem, and everything you will need is included with the operating system.
Open the Task Manager by pressing Ctrl + Shift + Esc. Click the "Performance" tab, and watch the CPU usage chart for a moment to establish a baseline. The idle CPU utilization should be less than 2 percent on a normally functioning system. If it says above 2 percent, then there is a program that is utilizing too much CPU power.
Click on the "Processes" tab, and scroll through the list of programs, keeping an eye on the "CPU" column. Most of the programs listed will read 0 percent. Find the program that is using CPU power, and note the name of the process. Ignore the listing titled "System Idle Process." It's entirely normal for it to show as much as 99 percent CPU usage.
Click on the process that is showing excessive CPU utilization. Click "End Process" to terminate it. Choose "Yes" on the confirmation window that appears. The process will now be forced to terminate, and CPU utilization will return to the normal range.