I used Norton (Symantec) for years, but it always needed to be uninstalled and re-installed. This got old, so I switched to McAfee, and during the 4 year subscription it worked flawless. Then I renewed with McAfee Total Protection (on 2 identical PC's). Not only do we get the not protected message almost daily with each auto-update, but also get a separate pop-up message that "Unknown PC or Device Connected." When going to the Network Map, etal, there is nothing unusual showing. I don't know why McAfee can't fix this with a download patch. McAfee's solution seems to be uninstall / reinstall. McAfee has gone down the road of Symantec. My next anti-virus/firewall subscription will be something else unless they can fix this.
RE: not protected and Unknown PC or Device Connected
This might happen when your the McAfee software was purchased from two different suppliers. For instance, you might have gotten it first from a 'partner' like Comcast and then, after the 4 years, puchased the software at the McAfee website. Somewhere the computer still thinks that it can download the virus signature files from the 1st location while somewhere else the program checks that it downloads from the McAfee site. Getting confused already? Me too... let alone the program....
While you're busy... wink you might want to check whether the Windows software is up-to-date too. Go to the Microsoft Update website, use the "Custom" button and install all the "critical" and "optional" updates.