Windows 8 Services

Windows Defender Mini-Filter Driver - Windows 8 Service

Windows Defender On-Access Malware Protection Mini-Filter Driver.

This service also exists in Windows 10.

Startup Type

Windows 8 edition Windows 8 Windows 8.1 Windows 8.1 Update 1
Core Boot Boot Boot
Pro Boot Boot Boot
Enterprise Boot Boot Boot

Default Properties

Display name:Windows Defender Mini-Filter Driver
Service name:WdFilter
Error control:normal
Group:FSFilter Anti-Virus

Default Behavior

The Windows Defender Mini-Filter Driver service is a file system driver. If Windows Defender Mini-Filter Driver fails to start, the error is logged. Windows 8 startup proceeds, but a message box is displayed informing you that the WdFilter service has failed to start.


Windows Defender Mini-Filter Driver won't start, if the FltMgr service is stopped or disabled.

Restore Default Startup Type for Windows Defender Mini-Filter Driver

Automated Restore

1. Select your Windows 8 release and edition, and then click on the Download button below.

2. Save the RestoreWindowsDefenderMiniFilterDriverWindows8.bat file to any folder on your hard drive.

3. Right-click the downloaded batch file and select Run as administrator.

4. Restart the computer.

Note. Make sure that the WdFilter.sys file exists in the %WinDir%\system32\drivers folder. If this file is missing you can try to restore it from your Windows 8 installation media.