Scenario :

This post describe how to fix SCCM maintenance windows reboot problems.

SCCM maintenance windows reboot Troubleshooting :

  • Check the Maintenance Windows properties

The maintenance Windows is set to a 2h duration :

SCCM maintenance windows reboot
  • Check the Deployment properties

The first step is to make sure that your deployment allows reboot:

My machine is a Windows 2012 (thus considered a server) and the option to suppress reboot is not selected.

SCCM maintenance windows reboot
  • Check if there’s overlapping maintenance Windows

Using the built-in report “Maintenance windows available to a specified client”, I can see that my maintenance Windows is applied correctly to my server and there’s no other maintenance windows applied.

SCCM maintenance windows reboot
  • Check RebootCoordinator.log

The log to watch for this type of “error” is RebootCoordinator. Let’s see what it has to say :

SCCM maintenance windows reboot

The interesting part is there :

ServiceWindowsManager has allowed us to Reboot – Maintenance window has permitted to reboot
Scheduled reboot from agent UpdatesDeploymentAgent – Updates were deployed at 11:03 AM and a reboot is required

Then just after it shows the following entries:

ServiceWindowsManager has not allowed us to Reboot
ServiceWindowsManager says that we will not be able to Reboot in the future
We may not Reboot ever. Sending ‘System May Never Reboot’ Status Message

We may not reboot… EVER… we’re doomed ! 🙂

So… we’re in a Maintenance Windows but our log says otherwise. (Even if my window is still valid until 12:30PM)

Resolution :

Check your restart settings in your client settings : (Administration – Client Settings – [Your settings Name] – Client Restart


As you can see, the Temporary notification is set to 90 minutes.

11:03AM + 90 minutes = 12:33PM

12:33PM is 3 minutes outside the maintenance window !

The important thing to remember is to take into account the notification time in your maintenance Windows. Reducing the notification time or increasing the maintenance window period fixed the issue.

By the way you can list the collections that have a schedule in maintenance windows with the report Configuration Manager – Collections. Simply sort by the columns Maintenance Windows.

SCCM maintenance windows reboot
Comments (5)

salman shahab

05.20.2019 AT 07:59 AM
Greate Post

michael parsons

12.20.2018 AT 02:57 PM
We had a small group of servers reboot with the " preferred reboot type 4" My question is if there is not a maint. schedule for the time of reboot, where would it get the "ok" from sccm to perform this reboot. "your reports were great for determining this" Also what is type 4. I know types 1-3 but not 4.


07.19.2018 AT 11:52 AM
Hey, great post. I am here for a strange issue. I deployed July 2018 updates on a server collection with no maintenance window and checked suppress reboot but some servers got restarted. What could be the reason?

Sachin Sharma

02.05.2018 AT 10:14 AM
Hi Benoit, We are facing a strange issue. Our servers are not rebooted during maintenance window. Even servers picked the maintenance window as we can see the service window manager log. Kindly assist me on this issue. Reboot Coordinator log says "ServiceWindowsManager has not allowed us to Reboot" . Please let me know if require more info regarding this case.