Serial port driver Service Defaults in Windows 11
Default Settings
| Startup type: | Manual |
| Display name: | Serial port driver |
| Service name: | Serial |
| Service type: | kernel |
| Error control: | ignore |
| Group: | Extended base |
| Path: | %SystemRoot%\System32\drivers\serial.sys |
| Registry key: | HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Serial |
Default Behavior
Serial port driver is a kernel driver. In Windows 11 it starts only if the user, an application or another service starts it. If Serial port driver fails to load or initialize, Windows 11 is starting up without warnings, however the error details are being logged.
Restore Default Startup Configuration of Serial port 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 Serial start= demand
3. Close the command window and restart the computer.
The Serial service is using the serial.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.