Smart card PnP Class Filter Driver (scfilter) Service Defaults in Windows 7

Smart card reader filter driver enabling smart card PnP.

Default Settings

Startup type: Manual
Display name:Smart card PnP Class Filter Driver
Service name:scfilter
Service type:kernel
Error control:normal
Group:PnP Filter
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\scfilter

Default Behavior

Smart card PnP Class Filter Driver is a kernel device driver. In Windows 7 it won't be started if the user doesn't start it. If Smart card PnP Class Filter Driver fails to start, Windows 7 attempts to write the failure details into Event Log. Then Windows 7 startup should proceed and the user should be notified that the scfilter service is not running because of the error.

Restore Default Startup Configuration of Smart card PnP Class Filter Driver

1. Run the Command Prompt as an administrator.

2. Copy the command below, paste it into the command window and press ENTER:

sc config scfilter start= demand

3. Close the command window and restart the computer.

The scfilter service is using the scfilter.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 7 installation media.