How to Scan Removable Drives With Microsoft Defender

If you regularly plug in USB drives or external hard disks, you’re opening a potential door for malware. The good news? Microsoft Defender—the built-in antivirus on Windows—can scan removable drives. You just need to know how to use it properly.

Here’s a step-by-step guide to scanning your removable drives using Microsoft Defender:

🔌 Step 1: Plug In the Drive

Insert your USB flash drive, external SSD, or any other removable storage into your Windows PC.

🛡 Step 2: Open Windows Security

1. Click the Start button
2. Type Windows Security and press Enter
3. In the left menu, click Virus & threat protection

🔍 Step 3: Start a Custom Scan

1. Under Current threats, click Scan options
2. Select Custom scan
3. Click the Scan now button
4. A window will pop up asking you to choose a location—select your removable drive and click Select Folder

Microsoft Defender will begin scanning that specific drive for threats.

⚙ Optional: Enable Automatic Scans for Removable Drives

Windows doesn’t scan USB drives automatically by default, but you can change that with a quick registry tweak:

Warning: Editing the Windows registry can cause system problems if done incorrectly. Only proceed if you’re comfortable with that risk.

1. Press Win + R, type regedit, and hit Enter
2. Navigate to:
   HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Scan
3. Right-click in the right pane, choose New > DWORD (32-bit) Value
4. Name it: DisableRemovableDriveScanning
5. Set the value to 0

Now, Defender will include removable drives in automatic scans.

🧼 Keep It Clean

After the scan, Defender will notify you if any threats were found. You can quarantine or remove them immediately.

Final Tips

• Always scan unknown USB drives before opening files
• Keep Defender updated for the latest malware definitions
• If you use third-party antivirus software, check if it also covers removable drives

Microsoft Defender is free, built-in, and powerful—don’t skip this simple step to keep your files (and system) safe.