USB Device Emulation Support Library (UdeCx) Service Defaults in Windows 11
Default Settings
| Startup type: | Manual |
| Display name: | USB Device Emulation Support Library |
| Service name: | UdeCx |
| Service type: | kernel |
| Error control: | normal |
| Path: | %SystemRoot%\system32\drivers\udecx.sys |
| Registry key: | HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UdeCx |
Default Behavior
USB Device Emulation Support Library is a kernel driver. In Windows 11 it starts only if the user, an application or another service starts it. If USB Device Emulation Support Library fails to start, the failure details will be recorded into Event Log. Then Windows 11 should boot up and notify the user about the UdeCx service startup failure.
Restore Default Startup Configuration of USB Device Emulation Support Library
1. Run the Command Prompt as an administrator.
2. Copy the command below, paste it into the command window and press ENTER:
sc config UdeCx start= demand
3. Close the command window and restart the computer.
The UdeCx service is using the udecx.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 11 installation media.