Thank you for reporting the issue. I checked if I am able to reproduce the issue on lab PC but had no luck. Also I do not see many customers reporting this issue. I would need the below details to understand what could be causing this problem and we can take it forward from there.
1. Does a reboot bring down the CPU usage? If yes, how long does it take before the CPU usage shoots back up?
2. Have you noticed any pattern on what triggers this issue? Example: Opening any specific program, etc.
3. Apart from McAfee, is any other security program or like installed?
4. What is the version McAfee installed? This can be identified from About window.
5. Are there any pending windows update?
Once you provide me the above information, we can coordinate and proceed further.