If McAfee Antivirus is not working fine on your Windows 7 or 8 or 10 system, then you have to first check the possible causes. Whether it is a compatibility issue or blocking issue or antivirus is not updated. Once you know the root causes, then it is easy for you to solve this problem on your own. The troubleshooting steps that you must follow while fixing this not working issue are listed below:

Delete any other antivirus from your system. Even temporarily remove any software that is blocking the proper functioning of antivirus.
Check the connectivity of the internet and make sure it should be stable and active.
First, uninstall and then re-install McAfee Antivirus on your Windows.
Try to update the device driver of the system.
Remove all the temporary and junk files stored in your system.
If you don’t want to waste time on solving the issue on your own, then call McAfee customer support to speak with professionals. The experts can resolve the issue by listening to your query first and then giving a proper and correct solution for the glitch confronted.