Plan 9 Redirector Driver (P9Rdr) Service Defaults in Windows 11

Plan 9 Redirector Driver.

Default Settings

Startup type: Manual
Display name:Plan 9 Redirector Driver
Service name:P9Rdr
Service type:kernel
Error control:normal
Path:%SystemRoot%\System32\drivers\p9rdr.sys
Registry key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\P9Rdr

Default Behavior

Plan 9 Redirector Driver is a kernel driver. In Windows 11 it starts only if the user, an application or another service starts it. If Plan 9 Redirector Driver fails to start, the failure details will be recorded into Event Log. Then Windows 11 should boot up and notify the user about the P9Rdr service startup failure.

Dependencies

Plan 9 Redirector Driver cannot be started, if the Redirected Buffering Sub System service won't start.

If Plan 9 Redirector Driver doesn't work properly, the P9RdrService service can't start.

Restore Default Startup Configuration of Plan 9 Redirector Driver

Before you begin doing this, make sure that all the services on which Plan 9 Redirector Driver depends are configured by default and function properly. See the list of dependencies above.

1. Run the Command Prompt as an administrator.

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

sc config P9Rdr start= demand

3. Close the command window and restart the computer.

The P9Rdr service is using the p9rdr.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.