This is a duplicate of this thread. Try to keep it to one thread so we can get all the questions and ansers in one place.

You might be able to go to Control Panel/Security Center/under Resources in the left hand column/Change the way Security Center alerts me/uncheck Virus Protection - Alert me if my computer might be at risk because of my virus protection software settings. This may turn off the popup, but not the antivirus software. Probably need to know which AV you use to know how to turn it off.

OK so try removing the left side and leave it off for a few days to see if heat is an issue. Is there a build up up crud under the fan you see mounted on the motherboard? This is the heatsink for the processor and it is designed to shut the computer down if it overheats for protection. Remove the power cord if you go in there and rest a bare arm or hand on the metal frame to eliminate static electric. You should seriously consider installing an anti malware program for greater protection. These do not run automatically but you update and run at intervals. Consider MS Essentials, Superantispyware, Malwarebytes or any other program you feel will keep you safe. Those mentioned are all free but pay attention during the install or you'll find yourself installing the 'for a fee' software.

I wasn't going to do anything because I'm supposed to get auto updates. Ususally when I get the Updates are ready message, I check and they are already installed. Well, I just checked and I have one update necessary. I'm doing it now, hoping that nothing is wrong. It's working, but boy is it slow. I do have virus protection. More scary though - I got a message the other day that a virus was innoculated. Here's hoping nothing is wrong. I can't stand these bored techno-geeks!! With all that we could use their talents for, they choose to do this. I'm sure they could get satisfaction and more money working their talents honestly.