Run an Offline Defender Scan (Windows)

An Offline scan restarts your PC and checks it before Windows fully loads, which catches stubborn malware that hides while the computer is running normally. It takes about 15 minutes, during which you cannot use the PC — so start it when you can step away.

Before you start

Save and close your work. The computer will restart on its own.

Steps

1. Click the Start button and open Settings (the gear icon).
2. Go to Privacy & security, then Windows Security. (On Windows 10 this lives under Update & Security instead.)
3. Click Virus & threat protection.
4. Under Current threats, click Scan options.
5. Choose Microsoft Defender Antivirus (offline scan).
6. Click Scan now, then confirm.

Your PC restarts and runs the scan on a blue screen. When it finishes, Windows starts back up. To see what it found, reopen Virus & threat protection and click Protection history.

If it finds something

Defender usually removes or quarantines threats automatically. If anything looks unresolved, or the problems continue, call me and I will take it from there.