1) Locate Microsoft Security Essentials antivirus software in Windows 7 or Windows XP which is a green icon with a white check mark in it.
2) Disable Real-time protection from Settings > Real-time protection. Uncheck the box and hit Save Changes:
3) Now launch your web browser and navigate to the web console. Proceed to download and install the software. When prompted to reboot the computer un-check the box to select "no" so the computer does not reboot. Now we need to set the exclusion path from the dashboard under Settings > Account Information > Paths to Exclude for Anti-virus software, or via the popup window after selecting to download the installer file.
4) Return to Windows Defender and set the exclusion path located in the previous step. Click Browse and locate the folder from above. Click "Add" and then "Save Changes"
5) Once completed, then reboot the computer.