DISMTools and Windows 10

[CodingWonders]

You may already know about the end of support for Windows 10 and what that entails. After 10 years, Microsoft ends support for Windows 10 today, October 14, 2025. A computer that still runs Windows 10 no longer receives security updates, unless you had enrolled it to the Extended Security Update (ESU) program, which protects the device with security updates until either 2026 (for consumers) or 2028 (for businesses).

Another implication of Windows 10 end-of-support is that software will eventually stop supporting Windows 10. Some developers have already established end-of-support dates for their software. For instance, Office will stop receiving security updates in a Windows 10 environment in 2028. Others may continue supporting Windows 10 for a much longer time.

Fortunately, there is good news for you if you run DISMTools on Windows 10. You will keep receiving program updates. However, there are some extra bits of information worth reading. So, in this post, you will see all relevant information about Windows 10 compatibility after end of support.

NOTE: this does NOT cover the IoT Enterprise LTSC 2021 version and similar editions, with support until, at most, 2032. This is for security updates. However, you'll still be affected by application support.

Windows 10 as a host

As stated earlier, Windows 10 systems will continue to receive DISMTools software updates for a longer time. However, there are key factors that can cause the program to stop supporting this operating system:

• .NET Frameworks: DISMTools or any component included with it may rely on an upgraded framework at some point in the future. Currently, all components rely on .NET frameworks supported by, at the very least, Windows 7 SP1. The unattended answer file creation component, UnattendGen, relies on .NET 9, which has been tested on Windows 8.1 and its corresponding Server variant using the self-contained version. However, when any of these components receive an updated framework that no longer supports old Windows versions, the following will happen:
  • If the main component (DISMTools) drops support for old Windows releases, it's game over. Consider reading migration options
  • If any of the secondary components drops support for old Windows releases, you will see a warning about unsupported operating systems, but the core program may still work
• Third-party libraries: DISMTools and its secondary components (for example, UnattendGen or the Sysprep Preparation Tool) may rely on libraries that won't support old Windows versions at some point in the future. This has happened in the past when the DISM API was first implemented. In that case, it led to the program dropping support for Windows 7 hosts. Libraries are another layer of dependency: your operating system may support the core framework, but if a library required for a program to function does not support that host system, it's not going to run the software. Fortunately, this has not happened ever since the DISM API implementation, but it's not like this will never happen again, because it most likely will

When I say old Windows releases, I mean Windows 8.1 AND Windows 10. Depending on the situation, the platforms will be discontinued either one sooner than the other, or at the same time. To help you plan your upgrade strategy, I will notify you with, at most, 2 WEEKS IN ADVANCE in releases and release announcements.

I will continue testing the newest DISMTools builds on Windows 8.1 and Windows 10 to determine when support will come to an end, and, of course, to test new features and fixes.

Windows 10 as an image

DISMTools will support Windows 10 images for the foreseeable future, even after support is dropped for Windows 10 as a host OS. So, for example, you can continue using DISMTools in Windows 11 to manage and service a Windows 10 image. In that case, compatibility is determined mainly by what the system DISM version supports. If it removes compatibility with Windows 10 (extremely unlikely), you'll have to rely on a different DISM binary. You can configure custom DISM binaries to use in the program settings.

In any case, continuing to manage and service a Windows 10 image is still not recommended, unless you really need to use Windows 10 for a specific purpose.

You can act now to remain calm

The end of support for Windows 10 can be your wakeup call that will help you prepare your migration strategy. You can choose from the following:

• Stay on Windows 10 but offline: use the version of DISMTools you're currently using for years to come, without access to any online features (like tutorial videos, release announcement feeds, or App Installer file downloads). You will have to slipstream updates manually, and if a newer release no longer supports Win10, you'll have to stick with a release containing issues that may already be fixed by newer versions of the utility
• Upgrade to Windows 11, either officially or unofficially: use the latest version of DISMTools on a system with the latest updates
• Switch to Linux and run Windows (10/11) in a VM: you'll run a supported OS and supported software in both the host and virtualized environments. However, the virtualized environment will not have access to all system resources. Refer to the next section for more details about DT on Linux.

Obviously, you pick your strategy. You decide what to do.

DISMTools on Linux systems?

DISMTools will never support a Linux system natively. This is NOT because I hate Linux but, rather, it's because of technical limitations.

On UNIX systems there is a tool that allows you to mount, unmount, and perform basic edits to Windows images: wimlib. However, it isn't enough. A full DISM implementation on a UNIX system can only be achieved when that system can call a Windows image's CBS API and can understand all the technologies (like AppX).

I will NOT work on a DISM port for Linux. It's simply too much work for me. Besides, I don't think Microsoft will like it...

Conclusion

To sum up, Windows 10 and older releases will continue to be supported as both hosts and images. However, it's a matter of time before this compatibility becomes unavailable (for hosts at least).

You will be notified when a version no longer supports old Windows releases and becomes Windows 11-only ahead of time, so you can plan your strategy. In any case, you should plan it now so you avoid taking risks.