You created your own or referenced existing shutdown.exe?
My favorite way to reboot, is running SHUTDOWN -R -T 0 -F
I only issue this command after verbally speaking to users and asking if they've saved their work, though. The -F is essentially "fu*k your open documents." Maybe it's a bad habit from working in the retail POS industry for a while.
It does install updates, but does not provide much of a friendly window of opportunity to shut down open applications. Depending on the OS it gives a short window to abort and save work.. But its damn aggressive.