Windows Defender Mini-Filter Driver (WdFilter) Service Defaults in Windows 8
Windows Defender On-Access Malware Protection Mini-Filter Driver.
Default Settings
| Startup type: | Boot |
| Display name: | Windows Defender Mini-Filter Driver |
| Service name: | WdFilter |
| Service type: | filesys |
| Error control: | normal |
| Group: | FSFilter Anti-Virus |
| Path: | %SystemRoot%\system32\drivers\WdFilter.sys |
| Registry key: | HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\WdFilter |
Default Behavior
The Windows Defender Mini-Filter Driver service is a file system driver. In Windows 8 it is being loaded by Boot Loader before Kernel initialization. If Windows Defender Mini-Filter Driver fails to start, the error details are added to Windows 8 error log. When the operating system startup is complete, the user is being notified that the WdFilter service hasn't been started.
Dependencies
Windows Defender Mini-Filter Driver can't start, if the FltMgr service is disabled or not available.
Restore Default Startup Configuration of Windows Defender Mini-Filter Driver
Before you begin doing this, make sure that all the services on which Windows Defender Mini-Filter Driver depends are configured by default and function properly. See the list of dependencies above.1. Run the Command Prompt as an administrator.
2. Copy the commands below, paste them into the command window and press ENTER:
sc config WdFilter start= boot
sc start WdFilter
3. Close the command window and restart the computer.
The WdFilter service is using the WdFilter.sys file that is located in the C:\Windows\system32\drivers directory. If the file is removed or corrupted, read this article to restore its original version from Windows 8 installation media.