In Microsoft System Center Configuration Manager 2007, maintenance windows (sometimes called service windows) provide administrators with a way to define a period of time that limits when changes can be made on the systems that are members of a collection. These windows restrict operating system advertisements, in addition to software update deployments and software distribution advertisements. When a maintenance window is applied to the collection, changes to collection member systems cannot typically be made outside of this time frame. This provides a safety net for administrators to ensure that client configuration changes occur only during periods when little or no impact to the organization will occur.

When maintenance windows are configured on collections that are targeted for software update deployments, you should consider the following:

• Each software update is given a default setting of 20 minutes to install and restart, if necessary (60 minutes for service packs). When the available time left in a maintenance window is less than this, the software update installation does not start until the next maintenance window. When you are planning a deployment to a collection with maintenance windows, take these defaults into consideration. For example, if a 2-hour maintenance window is configured on the collection and there are four software updates in a deployment, only three software updates are installed during the first maintenance window and the last update is installed during the second maintenance window.
  
  
• The following deployment settings affect how software updates are installed on client computers that have maintenance windows:
  
  
  • Allow system restart outside of maintenance windows: Specifies whether to allow system restarts for both workstations and servers outside of configured maintenance windows. By default, this setting is not enabled. This setting is beneficial when you want your software update installation to be completed on client computers as soon as possible. When this setting is not specified, a system restart is not initiated if the maintenance window ends in 10 minutes or less. This could prevent the installation from being completed and leave the client computer in a vulnerable state until the next maintenance window.
    
    
  • Ignore maintenance windows and install immediately at deadline: Specifies whether the software updates in the deployment are installed at the deadline regardless of a configured maintenance window. By default, this setting is not enabled and is available only when there is a deadline configured for the deployment. This setting is beneficial when there are software updates that must be installed on client computers as soon as possible, such as the updates in an expedited deployment.
    
    

Detailed information about maintenance windows is in the software distribution section, under Software Distribution Maintenance Windows. See the following topics:

About Software Distribution Maintenance Windows

About the Program Run Scenario Using Maintenance Windows

See Also