MSIX app attach is an application layering solution that allows you to dynamically attach an application (that is an MSIX package) to a user session. Separating the application from the operating system makes it easier to create a golden virtual machine image, and you get more control with providing the right application for the right user.

Previously, you had to use PowerShell scripts to enable MSIX app attach.  MSIX app attach capability is now available in public preview in the Azure portal and is integrated with Azure Resource Manager. This eliminates the need for custom scripts and makes it possible to publish your packaged applications to application groups with a few clicks.

Draft troubleshooting guide for MSIX app attach is available here.

Overview and requirements

Before you get started, make sure to fill out and submit this form to enable MSIX app attach in your subscription. If you don't have an approved request, MSIX app attach won't work. Approval of requests can take up to 24 hours during business days. You'll get an email when your request has been accepted and completed.

The following are the requirements to setup MSIX app attach in a Windows Virtual Desktop environment:

• Host pool in Windows Virtual Desktop with at least one active session host
• Host pool in the validation environment
• MSIX packaged application expanded into an MSIX image
• MSIX image is uploaded to file share
• The file share is accessible for all session hosts in the host pool
• When using a digital certificate that is not sourced from a CA please follow instructions here on each VM in the host pool 

This video walks through the MSIX app attach UI.

Deploy WVD (Windows Virtual Desktop) host pool

The steps for deploying a WVD host pool are outlined here. It is mandatory to provision the session host pool in the validation environment.

MSIX application

MSIX app attach requires an application packaged as MSIX. If you do not have an MSIX application you can use the MSIX Packaging tool to repackage a Win32 application to MISX application. Instructions are available here.

Prepare MSIX image

MSIX app attach needs MSIX application to be stored in a VHD(x). Steps on how to perform the expansion are available here.

If you do not have access to an MSIX application and MSIX images feel free to use these. They are provided without any guarantees and should not be used in production environments:

If you are using your own application, you will need to install the certificate used to sign the MSIX package.

Install certificates

If you are using the provided MSIX applications, there are two certs:

• For Chome, Edge, and Power Bi: WVDContosoAppAttach.
• For WVDMigration*, WVDMigrationFabrikam

Configure a file share

All session hosts need access to the file share with MSIX app attach packages.  This Tech Community blog covers the process.

Configure MSIX app attach via Azure portal

Open a browser, preferably in incognito mode, and load the following link: https://preview.portal.azure.com/?feature.msixapplications=true#home

In the search bar type Windows Virtual Desktop and click on the service.

Select a host pool where MSIX applications are to be delivered.

Select MSIX packages.

This will open the data grid with all MSIX packages currently added to the host pool.

Click + Add. This will open the Add MSIX package blade.

MSIX image path – this is UNC path pointing to the MSIX image on the file share. For example, \\storageaccount.file.core.windows.net\msixshare\appfolder\MSIXimage.vhd.

MSIX package – if a valid, resolvable, and accessible path is provided this drop-down will be populated by all the MSIX packages in the MSIX image.

Package applications – list of MSIX applications available in an MSIX package.

Display name – Optional display name to be presented in the interface.

Version – MSIX package version automatically delivered from parsing the package.

Registration type

On-demand – this is the recommended type of registration. It postpones the full registration of the MSIX application until and the user starts the application.

Log on blocking – this type of registration is executing during session logon hence adding time to session logon completion.

State – MSIX package has two states (Active and Inactive). When a package is active users can interact with it. Inactive packages are ignored by WVD and not delivered to users.

Click Save.

Publish MSIX application to an application group

In the WVD resource provider navigate to the Application groups blade.

Select an application group.

Note: During MSIX app attach preview MSIX app attach remote apps may disappear from the user feed. The remote MSIX apps can disappear from the user feed because host pools in the evaluation environment may get served by an RD Broker in a production environment (this happens when the RD broker optimizes to improve the end-user experience). Because the RD Broker in the production environment doesn't understand the date of the MSIX app attach remote apps, it won't display them.

Select the Applications blade. The Applications grid will display all currently added applications.

Click + Add to open the Add application blade.

Application source

• For desktop app groups the only source for applications is an MSIX package.

• For remote app group, there are three sources of applications.
  • Start menu
  • App path
  • MSIX package

MSIX package – display list of packages added to the host pool.

Display name – Optional display name to be presented in the Applications interface.

Description – Short description.

Note the options below are only applicable to remote application groups.

• Icon path
• Icon index 
• Show in web feed

Click Save.

Assign users to app group

Select app group.

Select Assignments

To assign individual users or user groups to the app group, select +Add Azure AD users or user groups.

Select the users you want to have access to the apps. You can select single or multiple users and user groups.

Select Save.

It will take five minutes before the user can access the application.

Change MSIX package state

Via the Applications grid

Select MSIX packages.

This will open the data grid with all MSIX packages currently added to the host pool.

Select one or multiple that need to have their state change and click the Change state button.

Via update package

Select MSIX packages.

This will open the data grid with all MSIX packages currently added to the host pool.

Click on Package name in the MSIX packages grid this will open the blade to update the package.

Toggle the State via the Inactive/Active button as desired and click Save.

Change MSIX package registration type

Select MSIX packages.

This will open the data grid with all MSIX packages currently added to the host pool.

Click on Package name in the MSIX packages grid this will open the blade to update the package.

Toggle the Registration type via the On-demand/Log on blocking button as desired and click Save.

Remove MSIX package

Select MSIX packages.

This will open the data grid with all MSIX packages currently added to the host pool.

Select one or multiple that need to be removed click the Remove button.

Removing MSIX application

Navigate to the host pool and select Application groups.

Select the application group from which the MSIX application is to be removed.

From the application group blade select Applications.

Select the desired application and click Remove.