Welcome to Justanswer.com, my name is Dustin.
I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
To get started, I need to know what type of computer you are using, a Windows XP, Vista, Windows 7, Windows 8, Windows 10 or a Mac.
If its a Mac, please check the OSX version as follows, Click the apple sign at the top left of your screen, then click about this mac. And then where it says version, send that to me as a reply.
Are you still using McAfee, or are you using a different antivirus software now?
Did you uninstall Mcafee already?
Please respond when you can and provide further info, thank you.