Hey everyone, I’m wondering if it’s possible to change an existing Windows 11 installation from a non-LTSC edition to LTSC — either online or offline. Is there any way to “attach” or convert the LTSC edition files without doing a full reinstall? Ultimately, I’m looking to get an installation image of Windows 11 LTSC version 26100.1. Any advice or detailed steps would be greatly appreciated. Thanks!
Yes. Since there is no direct upgrade path for online image servicing scenarios, you need to change the "EditionID" parameter in the registry (SOFTWARE\Microsoft\Windows NT\CurrentVersion\EditionID) in order to perform an in-place upgrade - as mentioned by @Windows_Addict. You can also modify the installation media beforehand as an alternative method. Other than a proper in-place upgrade, there exists blunt frankenbuilding, which does more harm than good. If you want to study Windows edition reconstruction, then see here. Well, you can either directly grab the official OEM installation media for IoT Enterprise LTSC, or opt for the 26100.1 (IoT) Enterprise LTSC evaluation ISOs - depending on your actual requirements.
Changing "editionID" is also part of that posts/thread Are not available on massgrave for quite a while now. You can find all here: https://forums.mydigitallife.net/posts/1830859
Never tried a none LTSC Ent to Ent LTSC. I do in place win11 update from win 10 LTSC build 1809 often to none LTSC Enterprise. Its not a clear cut way but it works when other methods has keeping apps and settings is greyed out. Use this tool "S-M-R-T JATD GUI _ v80.07". The license switcher tab allows upgrading a 1809 LTSC to win 11 Ent. I have been told the tool is not needed, but other ways keep apps and settings is greyed out. This tool allows for in place keeping apps and settings. It was available here on MDL years ago. I use win 11 build 22631.2428 as my upgrade OS, an early build of 23H2 as newer builds will convert the host PC to Pro. MAS will allow you to convert Pro back to Ent. so not a big problem other then upgraded PC is Pro converted. I will try to convert a win 11 Ent to a 11 LTSC Ent and report back here. We need a new tool that allows any way switching, upgrading win 10 any to win 11 any, win 11 any to win 11 any-keeping apps settings.
This is the tool that fixes unofficially supported upgrade paths: https://forums.mydigitallife.net/threads/upgradematrix-xml-fix-tool-very-beta.88518/ iirc Enterprise LTSC > Enterprise/Eductaion should be an official upgrade path.