Mcshield.exe is an integral part of the McAfee anti-virus program because it monitors processes, files and the registry to prevent any attempts to damage your computer. It automatically launches at start-up and, in many instances, consumes a lot of CPU memory, which is the reason people want to get rid of it. To that end, stopping its running process and removing it from start-up shuts it down and prevents it from operating.
Press "Ctrl," "Alt," and "Delete" together on your computer to access the Windows Task Manager. Click the "Processes" tab.
Click "mcshield.exe" and click "End Process." This will terminate this program's currently running process.
Click the Windows "Start" button and click "Run" or "Start Search" (Windows Vista users).
Type "services.msc" (without quotes) and press "Enter" to open the services window.
Click the "Services" button on the left panel. Scroll down the left panel and double-click "MCShield."
Click the "General" tab and select "Disabled" on the "Startup Type" window. Click "OK" to save the changes and close the Services window. This action will remove mcshield.exe from start-up and prevent it from running.
Shutting down mcshield.exe will prevent your McAfee anti-virus program from monitoring malicious processes and threats that may damage your computer.