**Symptom:** Windows Defender quick virus scan displays a message stating that it took an action, but there is no evidence of anything in either the Scan History or in the Event Viewer.
**Solution:** After banging my head for couple of days I gave up and reinstalled Windows 10 which eliminated the issue. The problem reoccurred after I installed Intel Driver & Support Assistant software which also installed Intel Computing Improvement Program. Uninstalling Intel Computing Improvement Program resolved the issue. I uninstalled both to be sure.