In this tutorial, I will show you how to perform an SCCM server in-place OS upgrade for a site server. We will upgrade our Configuration Manager Site Server running Windows Server 2022 to Windows Server 2025.
When you install Configuration Manager for the first time in your setup, you install it on a supported Windows Server OS. As time passes, newer versions of Windows Server are released, while older versions of Server reach the end of support. Hence, it is an important responsibility for administrators to keep the server OS updated to supported versions.
When it comes to upgrading the base operating systems on an SCCM site with multiple distribution points spread across the globe, things can get complicated. If a primary site server hosts the database server role, an in-place OS upgrade must be carefully planned. The clients will lose all communication with Management Point if the upgrade is unsuccessful.
In this guide, I will list all the prerequisites, server OS upgrade paths, and the procedure to upgrade the SCCM site server to Windows Server 2025. You can use these guidelines in your organization to upgrade the server infrastructure that runs Configuration Manager.
Site Server OS Upgrade Options
If you manage a Configuration Manager environment, there are three site server OS upgrade options available:
- In-place upgrade of operating system: A recommended approach for upgrading your existing server OS to the latest supported version.
- Recover a Configuration Manager site: Use this option if the site fails or data loss occurs in the site database.
- Site server high availability: Redundancy and high availability to the site server role.
Supported In-Place Server OS Upgrade Paths
Configuration Manager supports the following in-place upgrade of the server OS that hosts a site server and any site system role.
- In-place upgrade either Windows Server 2019 or Windows Server 2022 to Server 2025
- In-place upgrade from Windows Server 2016/2019 to Server 2022
- In-place upgrade from Windows Server 2012 R2/2016 to Server 2019
- In-place upgrade from Windows Server 2012/2012 R2 to Server 2016
Note: If your ConfigMgr is running on a Windows Server version that has reached EOL, you must immediately upgrade it to the next supported version. If this is not done, the server will not have the most recent security and important updates.
For more detailed information on the server in-place upgrade paths, check out all the upgrade paths for Windows Server, including the latest version, Server 2025.
Pre-upgrade tasks
The SCCM site server in-place OS upgrade requires a few checks before you start. These configurations or changes make your server ready for the upgrade. Let’s look at each of them in detail.
Install Server with latest Windows Updates
Before upgrading your Site Server OS, make sure to install all the latest Windows updates. Even though the Server upgrade setup wizard looks for the most recent updates, it will save you time if you do it beforehand.
After installing the updates, make sure you restart your server once. While not all updates necessitate a system reboot, critical ones do. Jump to the next prerequisite if your server is already patched.
Remove the WSUS role from the server
Microsoft recommends removing the WSUS role from the server before performing an in-place upgrade on the SCCM server. After performing several SCCM OS in-place upgrades, I do not believe this is necessary. Furthermore, I discovered that after the SCCM server OS upgrade, you will need to configure the WSUS post-installation tasks once, which should resolve your WSUS issues.
File-based replication health for site
If you’re upgrading the OS of the site server, make sure file-based replication is healthy for the site. Check all inboxes for a backlog on both sending and receiving sites. If there are lots of stuck or pending replication jobs, wait until they clear out.
- On the sending site, review sender.log.
- On the receiving site, review despooler log.
Download the Windows Server ISO
For an in-place upgrade, you’ll need to download the latest copy of the server operating system. In my case, I have got the ISO file for Windows Server 2025, as it is the latest version of the server.
Turn off Antivirus on Server during upgrade
Not all antivirus, but some, may interfere with the OS upgrade on the SCCM site server. From my understanding, the Windows Defender on the server shouldn’t cause any upgrade problems. In case you think the defender may block upgrades, you can turn it off using group policy during the in-place upgrade.
In some cases, third-party antivirus software may identify the upgrade as suspicious and attempt to block it. Therefore, make sure you temporarily turn your AV off during this upgrade and turn it back on once the in-place upgrade is complete.
Back up your Server and SCCM Database
Before performing the in-place OS upgrade of the SCCM server, you must back up the SCCM server. In the event of a disaster, a Configuration Manager site can be fully recovered using a backup of the databases.
Perform In-place OS upgrade of SCCM server
My current SCCM 2409 instance is running on Windows Server 2022 and I will be upgrading it to Windows Server 2025. Remember that only Configuration Manager 2409 and later versions support Server 2025 OS for site server and site system roles.
To start the upgrade, mount the Windows Server 2025 media. Right-click on setup.exe and select Run.
You should now see the Windows Server Setup launched. On the Install Windows Server page, click Next.
Enter the product for Windows Server 2025. If the entered key is valid, you’ll see a message: “Your product key works!”. If you don’t have the key, select Pay-as-you-go and click Next.
On the Select Image page, select Windows Server 2025 Datacenter (Desktop Experience). Click Next.
Accept the license terms for the Windows Server 2025 upgrade.
Select Keep files, settings, and apps and click Next.
The setup wizard prepares the files required for the upgrade. On the Ready to install page, verify your configuration and click Install.
The in-place upgrade of Server 2022 to Server 2025 begins now. The server automatically reboots during this process.
Once the upgrade is complete, sign in to your Configuration Manager site server. Go to System > About and under Windows specifications, you should find the edition and version details.
- Edition: Windows Server 2025 Datacenter
- Version: 24H2
Notice that after the SCCM server OS upgrade is completed, the Windows.old folder is present in the C:\ drive. The Windows.old folder contains files that give you the option to go back to your previous version of Windows. It is automatically deleted in approximately 10 days after the upgrade.
Fix WSUS Post Installation Tasks warning
After the SCCM primary site server OS was upgraded to Windows Server 2025, the server manager reported a warning requiring a configuration for WSUS. This is normal because any changes made to the operating system, particularly an upgrade, require the WSUS post-installation tasks to be initiated. If you haven’t uninstalled the WSUS before the in-place upgrade, this warning will appear. But not to worry; to fix this, all you have to do is click on Launch Post-Installation tasks.
After a few minutes, the required WSUS configuration is done and your primary site server is ready now.
Post Upgrade Tasks
Now that the OS upgrade has completed successfully on the SCCM site server, let us look at some of the basic checks that the administrator must perform post the upgrade.
Check the health of SCCM Components
Post the OS upgrade, you must check if all the components are healthy and there are no errors on the primary site server. To accomplish this, go to Monitoring > System Status > Component Status. Here you should see all your components listed along with their status. If you see the component status as OK, you don’t need to take any action. Any component reporting errors or warnings must be investigated.
Enable Third-Party Antivirus
Before the site server OS upgrade, if you had turned off your antivirus software, you can turn it back on now. Make sure Windows Defender is enabled, set for automatic start, and running.
SMS_EXECUTIVE and SMS_SITE_COMPONENT_MANAGER Services
Make sure the following Configuration Manager services are running post the OS upgrade:
- SMS_EXECUTIVE
- SMS_SITE_COMPONENT_MANAGER
- Windows Process Activation and WWW/W3svc
If you notice any other critical issues after upgrading the OS on the primary site server, then run a site reset. That’s it; you’ve successfully upgraded your Configuration Manager site server to Windows Server 2025.
What if the Primary Site Server OS Upgrade fails?
One common question among ConfigMgr administrators is what happens if the in-place OS upgrade fails on the primary site server. What happens if the OS upgrade ends abruptly with an error code or the blue screen of death? Well, if you are upgrading from Windows Server 2022 to Server 2025, I can tell you that in case of any errors, the Windows Server will roll back to its previous state. When an upgrade fails, the server displays an error code along with an error description. Coming to blue screen of death errors during an upgrade, you’ll have to resolve it using the actual error codes.
Still Need Help?
If you need further assistance on the above article or want to discuss other technical issues, check out some of these options.
