How to Fix High CPU Usage Problem: CPU usage is high. “MsMpEng.exe” shows high process. Solution: Uninstall all unwanted antivirus in Control Panel. Open Windows Defender and Look for update. If it is up to date, continue with Full Scan. For all the Detected items, change their Recommended Action to “Quarantine”. Observe for a week to see if the CPU usage is high. Problem solved.