I use Windows Defender on W10 as well. It seems to be doing the automatic quick scans. I don't know if full scans are done automatically or not. They would be useful if a virus got past the initial verification and then a later update taught Defender how to spot it.

I just looked into how it schedules stuff. There are two Task Scheduler items for Windows Defender. I see they are set to run only if the computer is plugged in. So if you never work with a laptop while plugged in, then Defender won't do background scans. In the last couple days, I've mainly been running on battery and then charging while the lid is closed. I haven't figured out where I should be going to change these settings.

My results look like this. Task Scheduler has a history of the results, but I can't tell what the tasks are actually doing. My virus definitions are as of yesterday. I think that is handled through Windows Update which probably runs on battery power.

(WD image.png)

WD image.png (34KB - 125 downloads)