Isapnp Service Defaults in Windows 11

Default Settings

Startup type: Manual
Display name:Isapnp
Service name:isapnp
Service type:kernel
Error control:critical
Group:Boot Bus Extender
Path:%SystemRoot%\System32\drivers\isapnp.sys
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\isapnp

Default Behavior

Isapnp is a kernel driver. In Windows 11 it starts only if the user, an application or another service starts it. If Isapnp fails to start, Windows 11 tries to record the error details into Event Log and restart the PC, using the Last Known Good configuration. If the Last Known Good configuration can't be used, Windows 11 startup process halts with a Stop error. If you disable or delete the isapnp service, Windows 11 won't start.

Restore Default Startup Configuration of Isapnp

1. Run the Command Prompt as an administrator.

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

sc config isapnp start= demand

3. Close the command window and restart the computer.

The isapnp service is using the isapnp.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.