Last week we had a customer who’s Windows 2008 R2 server stopped responding after selecting to restart the server. If updates are allowed to be applied when rebooting your server will try updating. In this case the server started applying server updates and was stuck at 32% for several hours and displayed the following
Please do not power off or unplug your machine
With the customers permission we did reboot the server and it came back to the same screen but proceeded to finish the updates after a few minutes.
A reboot may not fix your server but after several hours or days you will need to take action to proceed. You may end up needing to repair windows or remove certain files if the reboot does not work.