Is Migrating Existing VMs to the Updated Windows Server 2022 Image Mandatory After the .NET 6 Removal?

Hi Mattia,

Microsoft’s guidance points to the legacy image/offer being the thing that is being deprecated, not just the presence of .NET 6. The blog says the impacted Windows Server 2022 Marketplace images are deprecated “regardless of whether .NET 6 is actively used or not”.

So for existing standalone VMs, a full image migration is not strictly mandatory just to keep them running. Microsoft explicitly says you can either reimage the VM or remove .NET 6 from existing machines, and the deprecated-image FAQ says existing VMs continue operating normally because they boot from their OS disk, not the original image.

The catch is that this is only a runtime-viable answer, not a "forever stable" one. The legacy images will stop getting .NET 6 patching after June 2026, and the image deprecation reaches enforcement at the end of 2026. After enforcement, reimage is blocked, and VMSS scale-out from the deprecated image is blocked.

So the answer is:

• Standalone VM already in production: you can keep it running after manually uninstalling .NET 6, but you remain on a deprecated legacy image path.
• VM Scale Set or anything that depends on reimage/scale-out: moving to the new Windows Server 2022 image is effectively required to stay supportable.
• From a best-practice / supportability standpoint: Microsoft’s own direction is to migrate to the new offer and move apps off .NET 6 to .NET 8/.NET 10.

If you share whether you are running single VMs or VMSS, I can give you the exact migration decision tree.

Have a nice day!

TV

The breaking change is tied to the Azure Marketplace image contents and future servicing model, not to a hard requirement that all existing VMs be migrated to a new image.

From the provided information:

• Windows Server 2022 Azure Marketplace images currently include .NET 6.
• .NET 6 reached end of support on Nov 12, 2024; after that, Microsoft no longer provides updates (including security updates or technical support) for .NET 6.
• For Marketplace images, Microsoft is providing extended security updates for .NET 6 only within those images until May 13, 2025.
• .NET 6 will be removed from Marketplace media (the base images) at a later date (originally June 10, 2025, with that date now postponed and to be re‑announced).
• Going forward, Windows Server 2022 images will not include any .NET runtime (.NET 8 and later are not included). Users must handle .NET deployment themselves.

The documentation describes:

“Azure Marketplace media images for Windows Server 2022 currently include .NET 6, but going forward will not include a .NET version with the image (.NET 8 and later are not included with the image). Therefore, if you previously relied on the Azure Marketplace image to include the .NET 6 runtime then going forward you will need to handle the .NET deployment yourself.”

and

“Microsoft will provide security updates for .NET 6 in the Azure Marketplace media image beyond the official end of support date additional 6 months through May 13, 2025. .Net 6 will be removed from Marketplace media on June 10, 2025. Latest update: June 10 date had been moved out. A new date will be announced.”

From this, the supported guidance is:

1. The change is about what is included in new/updated Marketplace images and how .NET is serviced on those images.
2. After .NET 6 end of support, Microsoft does not support .NET 6 itself, except for the temporary extension on Marketplace images through May 13, 2025.
3. After .NET 6 is removed from the images, new VMs created from those images will not have .NET preinstalled, and any .NET runtime (e.g., .NET 8) must be deployed and managed explicitly.

The context does not state that existing VMs must be migrated to the new Windows Server 2022 image as a mandatory requirement. It only states that:

• If reliance was on the image to provide the .NET 6 runtime, that approach is no longer valid going forward.
• Applications should be updated to .NET 8 using tools such as the .NET Upgrade Assistant, and deployment of .NET should be handled explicitly (for example, via CI/CD using Azure Pipelines as in Build, test, and deploy .NET Core apps - Azure Pipelines).

Based strictly on the provided documentation:

• The breaking change is primarily about the image contents and the end of support for .NET 6, not an explicit requirement to recreate or migrate all existing VMs to a new image.
• A supported production posture requires not running on an out‑of‑support .NET runtime. That means upgrading applications to a supported .NET version (e.g., .NET 8) and managing that runtime deployment.
• The documentation does not say that keeping existing VMs (with .NET 6 removed and a supported .NET version installed and managed by the customer) is unsupported.

Therefore, from the available information:

• A full image migration is not documented as mandatory.
• The key requirement is to stop relying on the built‑in .NET 6 runtime and to move to a supported .NET version that is deployed and managed independently of the base image.

For production environments, the recommended path is:

1. Upgrade applications to .NET 8 using the .NET Upgrade Assistant.
2. Implement explicit deployment of the .NET 8 runtime (for example via Azure Pipelines or configuration management) on existing or new VMs.
3. Optionally, adopt the newer Windows Server 2022 images that no longer include .NET, to align with the new servicing model; this is recommended for consistency but not stated as a strict requirement in the provided documentation.

References:

• Windows Server images for November 2025
• Windows Server images for September 2025
• Windows Server images for August 2025
• Windows Server images for June 2022