It is also advisable to visit the McAfee support web site and search the Knowledge Center for 'high CPU usage':
Troubleshooting high CPU usage related to Disk I/O and McShield
https://kc.mcafee.com/corporate/index?page=content&id=KB67891
FAQs about McShield.exe and high CPU utilization when running On-Demand scans
https://kc.mcafee.com/corporate/index?page=content&id=KB85299&snspd-0815
How could I limit McAfee's CPU usage during scans?
https://community.mcafee.com/thread/81746?tstart=0