Follow these steps to troubleshoot the new Teams installation failure after uninstalling classic Teams:
- Confirm classic Teams removal method
- If classic Teams was user-installed (only one "Microsoft Teams" entry in Apps/Programs), it should be removed automatically after new Teams installs. No extra action is usually required.
- If there is a "Teams Machine-Wide Installer" entry, classic Teams removal is tied to that installer and Microsoft 365 Apps. Make sure the environment is not blocking the new Teams installation.
- Check for policy/registry blocks
- Some Group Policy or registry settings can block the new Teams MSIX package from installing.
- On the laptop, open the Local Group Policy Editor (gpedit.msc) and go to:
- Computer Configuration > Administrative Templates > Windows Components > App package Deployment.
- Ensure these policies are set to Not configured:
- Prevent non-admin users from installing packaged Windows apps
- Allow all trusted apps to install
- If these are set to block app installs, change them to Not configured (or have an admin do so) and retry the Teams installation.
- Check the specific registry keys
- The following keys can block new Teams MSIX installation:
- BlockNonAdminUserInstall
- AllowAllTrustedApps
- AllowDevelopmentWithoutDevLicense
- They may exist under:
-
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\AppModelUnlock
-
Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Appx
- If AllowAllTrustedApps is disabled, installation fails. Install the latest Windows cumulative update (KB5031455 or later, depending on OS) so that the new Teams app can install even when this policy is disabled, or adjust the policy as above.
- Ensure OS and Teams meet minimum requirements
- Make sure the laptop is on a supported Windows 10/11 build for the new Teams client.
- Install any pending Windows updates, especially October/November cumulative updates mentioned in the documentation, then retry the Teams installation.
- Rerun installation and review logs
- After adjusting policies and updating Windows, rerun the Teams installer.
- If the installation still fails, run the official pre-installation check script for new Teams (as referenced in the documentation) to identify remaining issues and follow its suggested resolutions.
- If classic Teams was removed manually
- If classic Teams was manually uninstalled and users are left without any Teams client, ensure that new Teams is deployed machine-wide (for example, via Microsoft 365 Apps or the bulk installer) so that users are not left without a Teams installation.
If the log still shows failures after these steps, focus on whether the error mentions MSIX, Group Policy, or blocked app deployment; those typically point back to the policy and registry settings described above.
References:
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