Serial UART Support Library (SerCx2) Service Defaults in Windows 10

Serial Class Extension V2 by Microsoft Corporation.

Default Settings

Startup type:Manual
Display name:Serial UART Support Library
Service name:SerCx2
Service type:kernel
Error control:normal
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SerCx2

Default Behavior

Serial UART Support Library is a kernel device driver. In Windows 10 it is starting only if the user, an application or another service starts it. If Serial UART Support Library fails to start, the failure details are being recorded into Event Log. Then Windows 10 will start up and notify the user that the SerCx2 service has failed to start due to the error.


Serial UART Support Library cannot be started under any conditions, if the Microsoft ACPIEx Driver service is disabled.

Restore Default Startup Configuration for Serial UART Support Library

1. Select your Windows 10 edition and release, and then click Download.

2. Save the Win10_SerCx2_Service_Startup.cmd file to a local storage device.

3. Run the saved file as an administrator.

4. Restart the computer.

The SerCx2 service is using the SerCx2.sys file that is located in the %WinDir%\system32\drivers folder. If the file is changed, damaged or deleted, you can restore its original version from Windows 10 installation media.