ACR task support for building Windows 2025 images

[mskwierczynski982]

What is the problem you're trying to solve
Currently there is no way that I'm aware of to build Windows 2025 containers using ACR task.
Given Windows Server 2022 will be EOL later this year we want to move forward with switch to 2025, since we are using ACR task to build Windows images we are blocked currently.

Describe the solution you'd like
I should have option to specify that I want to build Windows 2025 container, something like

az acr task create ... --platform Windows2025

Additional context
Right now it's failing with error:

Step 1/8 : FROM mcr.microsoft.com/windows/servercore:ltsc2025-amd64 ltsc2025-amd64: Pulling from windows/servercore a Windows version 10.0.26100-based image is incompatible with a 10.0.20348 host

[yizha1]

Hi @mskwierczynski982 ACR Tasks will be supporting Windows 2025, ETA: End of Feb, 2026

[PatrickSpies]

Any news on this? :)

[yizha1]

@mskwierczynski982 it is availabe in public regions now. Please give it a try.

[PatrickSpies]

Worked for me without any further changes (except updating the base-image for the Dockerfile) :)

2026/03/05 19:20:53 Successfully pushed image: <redacted>.azurecr.io/<redacted>
2026/03/05 19:20:53 Step ID: build marked as successful (elapsed time in seconds: 225.232314)
2026/03/05 19:20:53 Populating digests for step ID: build...
2026/03/05 19:20:59 Successfully populated digests for step ID: build
2026/03/05 19:20:59 Step ID: push marked as successful (elapsed time in seconds: 10.189964)
2026/03/05 19:20:59 The following dependencies were found:
2026/03/05 19:20:59 
- image:
    registry: <redacted>.azurecr.io
    repository: <redacted>
    tag: <redacted>
    digest: sha256:1eded9c17964e42925565ae69536030852a2ba29c444bff2b032dd53fe3e4bc1
  runtime-dependency:
    registry: mcr.microsoft.com
    repository: dotnet/framework/aspnet
    tag: 4.8.1-windowsservercore-ltsc2025
    digest: sha256:29a7aa8fe2a4ff6b5e21e71a188185ace3c249c9ceea4185cff9b275adede0a1
  git: {}
Run ID: dn2an was successful after 4m26s

[yizha1]

Hi @PatrickSpies Can you elaborate on what you meant by “except updating the base image in the Dockerfile”?

[PatrickSpies]

Sorry for the late response.. I meant building with az acr build --platform windows --registry ... worked for both

FROM mcr.microsoft.com/windows/nanoserver:ltsc2022

and

FROM mcr.microsoft.com/windows/nanoserver:ltsc2025

without changing anything else (e.g. the --platform-argument).