Teams MSI Override

[!IMPORTANT] Microsoft Teams is in the process of transitioning to the New Teams desktop client. The New Teams desktop client uses a completely different installation process which these scripts will not support. These scripts will therefore not be needed once the transition to the New Teams desktop client is complete, and this repository will be removed at that time.

Microsoft Teams supports installation through an MSI installer, referred to as the Teams Machine-Wide Installer. This installer is used by Microsoft Office to install Teams or may be used by organizations installing Teams through a deployment package.

The Teams Machine-Wide Installer does not normally get updated, and per-user instances of Teams installed into a user's profile will normally not be affected by changes to the Teams-Machine-Wide Installer.

There may be cases where an organization needs to update the Teams Machine-Wide Installer or forcibly update the per-user instances of Teams, perhaps for a critical security release, or if the normal update process is failing, or because a machine is shared, and new users are getting an outdated Teams installation.

In the event an organization needs to update the Teams Machine-Wide Installer, they can use a feature named MSI Override to update the MSI installed on a machine and allow per-user instances of Teams to update from the MSI.

For additional technical details on the Teams Machine-Wide Installer and MSI Override, please see Details

To implement MSI Override, you can use the PublishLatestVersion.ps1 and CheckMsiOverride.ps1 scripts.

Getting Started

PowerShell 5.0 (or greater) must be installed on the host machine. Click here for details on how to get the latest version for your computer.

PublishLatestVersion

The PublishLatestVersion.ps1 script will retrieve the most recent Teams MSI installers and store them onto a file share. This share can then be used by the CheckMsiOverride script.

Command

PublishLatestVersion.ps1 -BaseShare <share location> [-PreviewRing]

-PreviewRing will check for and download the version currently available in the preview ring. If you are currently running a preview version, this can be used to continue to pull the preview version while using this script package.

Usage

To use the script, follow these steps:

1. Download the latest version of the script package.

2. Create a file share (i.e., \\server\TeamsUpdateShare) which is accessible by all users which require the Teams MSI Override deployment. Ensure general users have read access, and only a few users, such as your IT administrators, have write access (these are your MSI Override Administrators).

3. Copy the PublishLatestVersion.ps1 script to a location available to your MSI Override Administrators.

4. Run the PublishLatestVersion.ps1 script, providing the path to the file share as follows:

   PublishLatestVersion.ps1 -BaseShare \\server\TeamsUpdateShare

At this point the file share should be populated with a new folder containing the latest Teams MSI installers, as well as a Version.txt file which indicates which version is the latest. Going forward the MSI Override Administrators can run the PublishLatestVersion.ps1 script to retrieve the latest Teams MSI installers at any time.

CheckMsiOverride

The CheckMsiOverride script is intended to run on user machines, and will set the required registry key, and update the Teams Machine-Wide Installer to the most recent version.

This script supports three methods of checking and retrieving an updated MSI: Share, CDN, and Package.

• The share method uses a share location populated by the PublishLatestVersion script to check for a newer version and to copy the MSI from.
• The CDN method has each client directly query if a new version is available and then downloads the relevant MSI directly from the Microsoft CDN server. Note that this method has each individual user downloading the files, and therefore can cause increased bandwidth usage if multiple users are executing the script at the same time.
• The package method requires the relevant MSI to be placed in the same folder as the script. This method is intended for deployment via package managers to allow all the relevant files to be placed in one location.

It must be run with Administrative privileges. It may be ideal to have it run from the SYSTEM account.

The script is signed, so the user executing the script on each machine will require an execution policy of at least RemoteSigned.

Command

CheckMsiOverride.ps1 -Type Share -BaseShare <share location> [-OverrideVersion <version number>] [-MsiFileName <MSI file name>] [-AllowInstallOverTopExisting] [-OverwritePolicyKey] [-FixRunKey] [-Uninstall32Bit]

CheckMsiOverride.ps1 -Type CDN [-PreviewRing] [-OverrideVersion <version number>] [-MsiFileName <MSI file name>] [-AllowInstallOverTopExisting] [-OverwritePolicyKey] [-FixRunKey] [-Uninstall32Bit]

CheckMsiOverride.ps1 -Type Package -OverrideVersion <version number> [-MsiFileName <MSI file name>] [-AllowInstallOverTopExisting] [-OverwritePolicyKey] [-FixRunKey] [-Uninstall32Bit]

• -Type <[ Share | CDN | Package ]> specifies which type of retrieval is used. Share is the default value if this parameter is not specified, for backwards compatibility.
• -BaseShare specifies the share location which has been populated by PublishLatestVersion.ps1. This is only valid with the -Type Share parameter.
• -OverrideVersion <version number> specifies target version number for the client to have. It is required with the -Type Package parameter, and is optional in the other cases.
• -PreviewRing specifies that the target version should be from the preview ring. It is only valid with the -Type CDN parameter.
• -MsiFileName <MSI file name> specifies the name of the MSI file that was previously used to install Teams. This is only required in rare cases where the file name was changed prior to installation, and the script is unable to determine the correct file name based on what is stored in the registry. It is optional for all -Type parameter values.
• -FixRunKey specifies that the script should correct missing or incorrect Run key values for the Teams Machine-Wide Installer. It is optional for all -Type parameter values.
• -Uninstall32Bit specifies that the script should uninstall a 32-bit installation of Teams so the 64-bit version can be installed on 64-bit Windows. It is preferred to run 64-bit Teams on 64-bit Windows. It is optional for all -Type parameter values.
• -AllowInstallOverTopExisting specifies that Teams can be installed instead of upgraded in a specific case. Please see below for further details. It is optional for all -Type parameter values.
• -OverwritePolicyKey specifies that the script should overwrite the AllowMsiOverride key. Please see bleow for further details. It is optional for all -Type parameter values.

AllowInstallOvertopExisting

When installing the Teams Machine-Wide Installer originally, it could have been installed in 3 main ways, relative to the current user:

1. Installed by any user using ALLUSERS=1 parameter
2. Installed by the current user without the ALLUSERS=1 parameter
3. Installed by a different user without the ALLUSERS=1 parameter

For scenarios 1 and 2, the script can perform an in-place upgrade of the MSI.

For scenario 3 the current user is not "aware" that the MSI has been installed, and so it is not able to do an in-place upgrade. In this case the script will, by default, exit with an error.

If you pass the -AllowInstallOvertopExisting switch into the script, it will permit the script to instead perform an installation of the MSI for the current user. This will overwrite the existing files, allowing them to be updated to the correct version.

powershell.exe -File \\share\TeamsUpdateShare\CheckMsiOverride.ps1 -BaseShare \\share\TeamsUpdateShare -AllowInstallOvertopExisting

If this occurs, however, two different users will have separate installation entries created. If either user uninstalls the Teams Machine-Wide Installer, the files will be removed, and it will be shown as uninstalled for the user performing the uninstall, but the second user will still show an installation entry present, even though the files have been removed.

OverwritePolicyKey

By default, the script will populate the AllowMsiOverride key only if it does not already exist. Therefore, if your organization wants to push a value of 0 to some users, this value will remain even if the script is ran.

If you want to forcibly reset the value back to 1 for all users, you can pass the -OverwritePolicyKey switch.

powershell.exe -File \\share\TeamsUpdateShare\CheckMsiOverride.ps1 -BaseShare \\share\TeamsUpdateShare -OverwritePolicyKey

Share Type With Scheduled Task

The CheckMsiOverride.ps1 script can be deployed in various ways; we will provide an example here using Scheduled Tasks.

To deploy this script as a Scheduled Task you can use the following steps:

1. Download the latest version of the script package.

2. Copy the CheckMsiOverride.ps1 script to the file share you created (\\server\TeamsUpdateShare\CheckMsiOverrride.ps1), or any other equally accessible location per your organizations policies.

3. Create a scheduled task which executes the script as follows:

   powershell.exe -File \\share\TeamsUpdateShare\CheckMsiOverride.ps1 -Type Share -BaseShare \\share\TeamsUpdateShare

4. Specify a schedule that is appropriate for your organization. If no update is required, the script will make no changes, so there are no issues running it often (such as daily).

Package Type

If you are building a package with this script you can use the following steps:

1. Download the latest version of the script package.

2. Copy the CheckMsiOverride.ps1 script to the package directory.

3. Download the latest 32-bit and 64-bit Teams MSI, either from the Teams website or use the PublishLatestVersion script to retrieve them for you.

4. Place the Teams_windows.msi and Teams_windows_x64.msi into the folder with the CheckMsiOverride.ps1 script.

5. Determine the version number for this MSI, either by installing locally or extracting the files and looking at the properties of the Teams.exe file contained inside. If you used the PublishLatestVersion script, the version number is the folder name they are placed into.

6. Have the package execute the script similar to as follows, using the proper location for the script for your package deployment software:

   powershell.exe -File CheckMsiOverride.ps1 -Type Package -OverrideVersion <version number of the MSI installation>

Diagnostics

CheckMsiOverride.ps1 will save a trace file to %TEMP%\TeamsMsiOverrideTrace.txt

It will also write to the Application event log with the source "TeamsMsiOverride" for any failures, or if an update completed successfully.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.