Microsoft on MSIX at AppManagEvent 2026
Microsoft returned to https://appmanagevent.com/ last week and provided updates on the future evolution of MSIX. Product Manager, and owner of MSIX and Windows App SDK for developers, Roy MacLachlan had an open conversation with the audience filled with transparency on what they are working on next.
While dates were not provided, Roy indicated that his teams are focused on filling the gaps between App-V and MSIX, as well as MSI and MSIX.
Probably the most important of those gaps is the lack of support for device drivers. Today, both App-V and MSIX do not support drivers in the application package and we need to deal with these external to the package. It is not yet clear how this support will work, but it looked like there will be a new AppXManifest extension to specify a driver installer file and inf file. This is my personal guesses on this: 1) the package probably requires elevation to install, just like a package with a service, which is no big deal. 2) I would expect this requires an OS update. Microsoft has become a bit loose in recent years about what can go in a monthly feature release versus annual release but my guess is that this is more likely to need an annual release so unless that support is hidden (as it is currently unusable) in 26H2 that means 27H2. 3) IT Pro’s don’t always get a separate driver installer and I’m not sure if that scenario will be covered by Microsoft – I may need to add additional help in TMEditX for repackaging those apps.
The second big item mentioned is additional support for CustomInstallActions. While we already have first-run scripting available via the PSF, Microsoft added a desktop6:CustomInstallAction for game developers previously that supports an exe/msi installer that is installed parallel to the package. The details in the schema were bare-bones and seemingly intended for a developer, rather than repackaging.
We have not been using this in repackaging, as we have a somewhat reasonable solution via the PSF scripting as long as elevation is not needed. Still, an install time option rather than first run can open up to more scenarios. The other reason we have not been using it is that there is issues around the uninstall associated with it. This is what Roy said they were looking into.
Based on what I heard from Roy, I did some more digging and have now found more details on current support outlined to developers “game development kit” here:
And while I shutter at the thought of bringing the issues we see in Custom Actions of MSI installers to MSIX, hopefully Microsoft will keep developers honest and in the future we can have a perfectly clean uninstall even with these CustomInstall actions. There may also be possibilities for third-party folks to leverage this capability in repackaging scenarios, but that is some serious research to be done.
These two items are probably the biggest gaps we see out there today for MSIX. Roy was also forthcoming in stating that they are not focused on improvements to the Microsoft MSIX Packaging Tool at this time. This is not really news to us; Microsoft created a base upon which third party developers (like me) are leveraging while Microsoft continues to add capabilities to the format and runtimes.
It is fantastic to see Microsoft coming back out and being transparent with the customer base. While one conference event is not enough to overcome the lack of information over the past few years, if you haven’t noticed it, Microsoft’s Howard Kapustein has been blogging regularly since May in the “InsideMSIX” site, helping to explain many of the Why/How questions and undocumented implementation details that official documentation does not touch. If you have read this far into this post, you should absolutely bookmark this link:
https://devblogs.microsoft.com/insidemsix
Tim Mangan is the owner of TMurgent Technologies, LLP, a company focused on the Microsoft MSIX and App-V technologies offering training, consulting, and software to allow Microsoft customers to adopt the future of software – MSIX.
Tim Mangan is the owner of TMurgent Technologies, LLP, a company focused on the Microsoft MSIX and App-V technologies offering training, consulting, and software to allow Microsoft customers to adopt the future of software – MSIX.
