This just happened to me again – I remote into a server and I'm greeted with the message that Windows will restart in 15 minutes to finish installing updates.
So far I've been able to abort the imminent shutdown by killing the WU service but I have 11 servers (all 2012) and this is getting monotonous.
I’ve found some registry changes to force the shutdown after 3 days regardless if a user is logged in or not but that leaves me with more unanswered questions. 3 days is kind of vague, 72 hours from the time the last update completed would tell me a bit more. Ultimately I would like to pick the time when the restart occurs (like overnight)
What are you guys doing to address this issue, what works??