Defend yourself!

So besides the strange problems I'm having waking up my computer from sleep mode, screen saver, or when I close and open the lid -it's set to do nothing- (the screen flashes on and off for maybe a minute before slowly coming back to life), or the random times it decides to shut down or restart itself without asking, I am still having problems with Windows Defender!

This is the explanatory message I've received for months whenever I tried to update it:




However, just this week my Piece of Dell volunteered this helpful notice while I wasn't even using the machine: