When my computer spiked to 90% CPU usage out of the blue, I stared at the Task Manager’s Processes tab for a while and terminated a few processes. I hoped it would resolve the problem, but nothing changed. The Task Manager tends to hide the real triggers for certain problems, so I switched to Event Viewer. Within minutes, I found the process and error that were hammering my processor. Once I’d dealt with them, CPU usage dropped and stayed normal. I’ve stopped using the Task Manager as much ever since.