Windows 2008 Server R2 hangs on "Preparing to configure Windows. Do not turn off your computer"

Last night I started installing updates on a Windows 2008 R2 box but when I had my dinner and returned to my computer I got pissed off seeing the server stalled at

and I could not RDP into the OS. I spent ca. half an hour waiting for something to happen, then, made a short google search. It turned out that if I connected to this OS via the services.msc console of an other server being in the same domain network I could see that WINDOWS MODULES INSTALLER Service was stuck in Stopping state.
Using the built-in Sysinternals utils:

taskkill /S hostname /IM trustedinstaller.exe

or

sc \\computername queryex TrustedInstaller
taskkill /s computername /pid /f

...I could have been able to terminate that task. According to some internet records if I had done so, my server would have restarted without a hitch. Luckily enough, after entertaining me for more than one hour (-meanwhile actualy doing nothing-) this damn server finally restarted by itself! After the reboot it installed the updates and got ready in less than 5 minutes.
So, in case you are here because you are in the same business as I was, now you'd better have some coffee and wait patiently instead of roughly interfere.