SOLVED! - 100% High CPU Usage of Microsoft Security Essentials MsMpEng.exe

SOLVED! - High CPU Usage of Microsoft Security Essentials

I've at least two laptops, after installing Microsoft Security Essentials, the CPU usage jumps up. Stopping or uninstalling it resolved the problem, which isolated the source to be Microsoft Security Essentials itself. After some research, this works for me as a workaround this problem.

1. Run Task Manager, find the process with high CPU usage. (Sorting by CPU may help you find it)
2. Likely you will find "MsMpEng.exe" has taken much of your CPU time
3. Now go to  your Microsoft Security Essentials, click on the "Settings" tab. Select"Excluded files and locations"
4. Browse to "C:\Program Files\Microsoft Security Client\MsMpEng.exe", Ok and press Addbutton to add the file to your list of excluded files and locations. Press Save changesbutton.

Same method applies to other trusted files. You should see the CPU usage drops down dramatically.