Serial UART Support Library (SerCx) Service Defaults in Windows 8

Serial Class Extension by Microsoft Corporation.

Default Settings

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

Default Behavior

The Serial UART Support Library service is a kernel device driver. In Windows 8 it will not be started until the user starts it. If Serial UART Support Library 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 SerCx service hasn't been started.


Serial UART Support Library can't start, if the Microsoft ACPIEx Driver service is disabled or not available.

Restore Default Startup Configuration for Serial UART Support Library

1. Select your Windows 8 edition and update pack, and then click Download.

2. Save the Win8_SerCx_Service_Startup.cmd file to a local storage device.

3. Run the saved file as an administrator.

4. Restart the computer.

The SerCx service is using the SerCx.sys file that is located in the %WinDir%\system32\drivers folder. If the file is corrupted or deleted, you can put it back in there.