Maintenance Windows can be set at the following ways:
- In ConfigMgr 2007: Rightclick on the collection, and choose: "Modify Collection Settings" > Maintenance Windows tab
- In ConfigMgr 2012: Rightclick on the collection, and choose: "Properties" > Maintenance Windows tab
Choose to create a new schedule here, and set properties for the right Service Window. I my case this will be every saturday between 13:00 and 17:00
When configuring Patch Management jobs in ConfigMgr 2012, properties can be set for Maintenance Windows. In the "Automatic Deployment Rule", used for Patch Management, there can be options set to "perform activities outside any defined maintenance windows". Normally this will not be the case.
There can also be options set to suppress reboots on servers and workstations. That way Software Updates will be installed within the Maintenance Window, while rebooting the system will not be done. Then this will be an manually action.
Now have a look at the server where Software Updates are advertised. When Scan Cycle has been run, and updates are needed for the system, an icon will be available in the System tray.
When rightclick on the icon, two options will be available. "Open Software Center" and "View Required Software". Both will have different functionality. When starting "Open Software Center" the following is possible:
There are Software Updates available, but not installed yet. This because of the Maintenance Window! Status here says: "Past due - will be installed". You can also have a look at Options here. There will be settings available for Remote Control and Power Management also.
When choose Schedule here, it is still possible to overrule the Maintenance Window, and install software directly. This is a manually action which can be done per system, which is most of times not recommended. Just leave it.
When starting "View Required Software" it is possible to change software installation settings also. They will be also available in Software Center > Options screen. Again there is a possibility here to install them directly, or "outside the configured business hours".
Best thing is leave these settings alone, and trust on the already configured Maintenance Window. That way you can make sure that installation and/or rebooting is only done within the Service Window!