Windows: Server stuck in shutdown after installing patches

One of my servers in my labenvironment refused to gently reboot after installing a ton of patches that I.. uhm.. forgot to install.
The “restart-computer -computername DC1” cmdlet wouldn’t do anything, as it returns with : Restart-Computer : Failed to restart the computer dc1 with the following message: A system shutdown is in progress.

Figures, the server is physical, and about an hour drive away.

The (somewhat crude) solution:
Use PSkill.exe to kill the TRUSTEDINSTALLER process. (Note: this is not recommended, but what the hell, this is a testenvironment).

1. Download the utility here
2. Extract it somewhere, open a elevated CMDlet window, and CD yourself into the exctracted folder.
3. Use this command to kill the respective hangig process: pskill.exe \your-server your-process (In my case: pskill.exe DC1 TRUSTEDINSTALLER).

The server then booted after about a minute, and about 15 minutes later it was available through RDP.