Running a quick scan on Windows Defender is simple and can be done in just a few clicks.
Windows Defender can be found in the task bar at the bottom right hand corner of your screen near the time. I recommend that prior to running any scan you right click on the shield and click Check for protection updates to ensure you have the most up to date virus definitions.
To run a quick virus scan simply right click on the shield and select Run quick scan
This will open a new screen and show the scan status
If after running the quick scan this finds no infections and you suspect your machine is infected you can run a deeper scan by right clicking and selecting View security dashboard
Select Virus & threat protection
Click Scan options
I recommend that you go straight for a full offline virus scan as this will scan every file on your device thoroughly.