Defender can do this if its in the midst of scanning, and occasionally if you are using it while it is scanning this seems to stop it for finish it keep it perp

Defender can do this if its in the midst of scanning, and occasionally if you are using it while it is scanning this seems to stop it for finish it keep it perpectually scanning (depends what you are doing). My advice, shut everything down, pop up defender and let it run all the way through. Also ensure all windows updates are done and installed - the background update manager can kill laptops in my experience, so again its best to let it get its job out of the way before using the laptop.