Windows Update, SCCM and Machines not obeying Maintenance Windows

[dverbern]

I manage windows updates on our server fleet, using SCCM 2012 R2 SP1.

Despite having clear-cut Maintenance Windows for our servers, we are still finding cases of individual servers having restarted unexpectedly.

 

In each case, the %Windir%\WindowsUpdate.log shows:

 

The process C:\Windows\system32\svchost.exe (ComputerName) has initiated the restart of computer ComputerName on behalf of user NT AUTHORITY\SYSTEM for the following reason: Operating System: Recovery (Planned)

Reason Code: 0x80020002

Shutdown Type: restart

As for why it restarted, the same log has the segment:

Client has determined it is safe to reboot without warning. Rebooting now...

This wasn't during a Maintenance Window, mind you.

Not all our servers are doing this. I've read online about Windows Update and SCCM and some posters mention that there are possible Group Policy changes that are needed to be made.

This surprises me, because I always thought that when you install an SCCM client on a machine, it leverages Windows Update to push out updates, changing Windows Update behaviour to suit what we configure in SCCM.

Adding to my confusion is the fact that different server OS seem to have different WIndows Update settings after SCCM client is installed, see attachments.

Does anyone have any clues as to why servers might be ignoring maintenance windows in some cases? I can confirm we don't have a case of multiple maintenance windows becoming cumulative or anything like that. Are there any Group Policy settings that users of SCCM have to make in order for workstations or servers to properly follow SCCM's instructions?

[g-fx]

had this before .. its windows update not sccm doing it:

 

http://www.windows-noob.com/forums/topic/8000-machine-restarted-automatically-last-night/