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impete-9406 asked RoyLi-MSFT edited

Specific questions about Windows 11 Store Deployment - MSIX, signing, EXE and VST3 (DLL)


I have some specific questions about signed MSIX deployment through the Windows 11 Store, that I've not been able to find answers to.


I have a 64-bit C++ application (WIN32), deployed and sold through the Microsoft Windows 10 Store using the UWP adaptor layer from Microsoft.

I want to deploy this in the Windows 11 Store, but additionally with:
- the ability to load 3rd party DLLs (specifically: audio plug-ins in VST3 format) from an industry-standard folder
- the ability, at time of installation, to additionally deploy a signed VST3 plugin (again, this is a DLL) to a industry-standard folder

By way of experimentation, I can easily create a .MSI file that deploys non-signed version of the EXE (without the UWP adaptor) and my VST3 DLL where I want them. This EXE can load-up 3rd-party VST3 DLLs as expected, and my VST3 DLL can be loaded by other audio authoring tools.

I can see how to convert the .MSI file into a .MSIX file.

However, I've not found out how to create a .MSIX file that is compatible with Windows 11 Store Deployment

My three questions are:

1) I am not at all clear how I would get a certificate that will sign my application. For my current UWP-adapted C++ .EXE, this signing is handled automatically through Windows Visual Studio 2019. Will this still be the case for my .MSIX file?

2) I am not at all clear that what I want - deploying both a signed .EXE and signed .DLL - will be supported for paid, auto-updating Windows 11 Store applications. Is this supported? And if not, why not?!

3) Assuming the above works - am I correct in assuming that I'll be able to sell my application (EXE, VST3 DLL) to Windows 10 Users via an updated Windows 10 Store?

Best wishes

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For the first question, the new Windows Store enables the developer to upload their desktop apps directly, you could just upload your win32 package without packaging it as a msix package. You could refer to this document: publish traditional desktop apps.

For the second question, I'd suggest you open free support ticket here: Contact Us. Go to Contact us, find Non-Technical Support - Dashboard and choose CHAT NOW or
. You could talk to the store team directly and confirm this issue.

For the third question, The new Microsoft Store is the same on Windows 10 or Windows 11. If you had uploaded your app to the new Microsoft Store and published it successfully. then your app should be available in the updated Windows 10 Microsoft Store app and the Windows 11 Microsoft Store.

1 Vote 1 ·

Hi Roy,

Wow - fast response. Thank you very much!

Both my questions below are follow-ups to the first question above. I'll submit an incident as you describe for the second question, and many thanks for explaining on the third one.

New Question 1 - it isn't at all clear if I upload a win32 (non-UWP) app, that Microsoft Windows 11 Store will allow:
a) me to sell the app as a signed application...
b) ... which users can auto-upgrade through the store as we update the app (and as we update the version number)

The reason I'm not clear on this? My reading is that for a) and b) to be true, we need to bundle as a MSIX file.

What is the correct understanding of how this is intended to work?

New Question 2) furthermore, whether we distribute a win32 (non-UWP) app, or MSIX (depending on what is required from above), how do we sign for:
c) internal testing
d) store deployment

The reason I'm not clear? UWP apps (Windows Desktop Bridge adaptor around C++ apps ... i.e. what I already sell via the Windows 10 Store) are what I understand to be referred to "Packaged" apps. Those apps are "packaged" when I select the appropriate "Publish" menu item from Visual Studio - creating a pair of app/cert for internal side-load testing, and a separate bundle file to upload to the store; all of these are signed automatically. It simply isn't clear what would happen with a "plain" win32 app or indeed an MSIX file.

Many thanks!

0 Votes 0 ·

Just FYI - submitted as incident SR1528285809 ... thanks.

Looking forwards to your response to my other two (new) questions!

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