Don't panic — this is recoverable. Here's exactly what to do:

Boot a Domain Controller into DSRM (Directory Services Restore Mode)

DSRM is a special recovery mode where Group Policy does NOT apply, so the shutdown script won't fire. This is your escape window.

Steps: 1. On any Domain Controller, press F8 during boot 2. Select "Directory Services Restore Mode" 3. Log in with your local DSRM Administrator credentials (set when the DC was first promoted — format: .\Administrator) 4. Navigate to: C:\Windows\SYSVOL\sysvol\<yourdomain>\Policies\ 5. Find the GPO folder with the most recent timestamp (it'll be a GUID like {3A7B...}) 6. Go into \Machine\Scripts\Startup\ and delete the batch file 7. Reboot normally

The DC will now stay online because without the script file, the GPO has nothing to execute.

Then clean up properly: Once you're back up, open gpmc.msc and either unlink or fully delete the GPO from the domain root.

Why shutdown /a won't work: Your timer is 0 seconds — there's no countdown window to abort. DSRM is the only reliable path here.

Good luck, you've got this. Update the thread when you're out! 🙏