Fix Microsoft Teams Signs Out Repeatedly After a Windows Update

After installing a Windows update, Microsoft Teams may sign you out every time you close and reopen the app. This happens because the update resets the app’s cached credentials and disrupts the token refresh process. In this article, you will learn why the update breaks the sign-in state and how to fix it with a few targeted steps.

The fix involves clearing the Teams cache, repairing the app, and re-signing in with your work account. You will also learn how to prevent the problem from recurring after future updates.

Why Windows Updates Cause Teams to Sign Out Repeatedly

When Windows installs a feature update, it may reset the permissions on the AppData folders that Teams uses to store authentication tokens. The token cache is stored in %appdata%\Microsoft\Teams. If the update changes the folder’s security descriptor, Teams loses the ability to read the token file. The app then treats you as a new user and forces a fresh sign-in.

Another cause is the Windows credential manager. The update can clear or invalidate the cached credentials that Teams uses to refresh tokens silently. When the refresh fails, the app signs you out to protect the account.

Finally, if your organization uses conditional access policies, the update might change the device state. The policy then requires a new authentication, which appears as a sign-out loop.

How Token Refresh Works in Teams

Teams uses OAuth 2.0 with refresh tokens. The app stores a refresh token locally. When the token expires, Teams uses the refresh token to get a new access token without asking you to sign in. If the refresh token is corrupted or missing, the app cannot refresh silently. It then shows the sign-in screen.

Steps to Fix Teams Sign-Out Loop After a Windows Update

Follow these steps in order. Do not skip the cache clearing step, because it removes the corrupted token file.

1. Sign out of Teams completely
   Open Teams, click your profile picture at the top right, and select Sign out. Wait for the app to return to the sign-in screen.
2. Close Teams and all background processes
   Right-click the Teams icon in the system tray and select Exit. Press Ctrl+Shift+Esc to open Task Manager. In the Processes tab, look for any Teams process and right-click it, then select End task.
3. Clear the Teams cache folder
   Press Win+R to open the Run dialog. Type %appdata%\Microsoft\Teams and press Enter. Select all files and folders in this directory and press Shift+Delete to permanently delete them. Do not delete the Teams folder itself.
4. Repair the Teams app
   Open Windows Settings by pressing Win+I. Go to Apps > Installed apps. Find Microsoft Teams, click the three-dot menu, and select Advanced options. Click the Repair button and wait for the process to finish.
5. Restart your computer
   Restart Windows to ensure all changes take effect. Do not open Teams before the restart completes.
6. Sign in to Teams again
   Open Teams and sign in with your work or school account. If you are prompted for multi-factor authentication, complete it. Teams should now stay signed in.

If Teams Still Signs Out After the Main Fix

If the problem persists, the issue may be in the Windows credential manager. Follow these steps to clear the stored Teams credentials.

1. Open Credential Manager
   Press Win+S, type credential manager, and open the Control Panel app.
2. Remove Teams and Microsoft Office credentials
   Click Windows Credentials. Scroll to find entries that contain Teams, MicrosoftOffice16, or MicrosoftAAD. Click the arrow to expand each entry, then click Remove.
3. Restart Teams
   Close Teams completely, then reopen it and sign in again.

If Teams Still Has Issues After the Main Fix

Teams Shows a Blank Sign-In Screen After Clearing Cache

Clearing the cache may remove some necessary app files. To fix this, reinstall Teams completely. Go to Windows Settings > Apps > Installed apps, find Microsoft Teams, click the three-dot menu, and select Uninstall. Then download the latest version from the Microsoft 365 portal and install it.

Teams Signs Out on Every Restart, Not Just After Updates

This usually indicates that the Windows update changed the folder permissions permanently. Right-click the %appdata%\Microsoft\Teams folder, select Properties, go to the Security tab, and ensure your user account has Full control. If it does not, click Edit and grant Full control.

Your Organization Blocks Token Refresh After the Update

Conditional access policies may require a new device registration. Contact your IT admin and ask them to check the sign-in logs in the Azure portal. They can see whether the refresh token is rejected because of a device compliance issue.

New Teams Desktop vs Teams on the Web: Key Differences

Item	New Teams Desktop	Teams on the Web
Token storage	Local cache in %appdata%	Browser cookie storage
Impact of Windows updates	Can corrupt the token file	No impact from Windows updates
Sign-out behavior	Signs out if token refresh fails	Stays signed in until cookie expires
Repair method	Clear cache and repair app	Clear browser cookies and site data

If you prefer to avoid the sign-out loop entirely, you can use Teams on the web as a temporary workaround while you fix the desktop app. However, the web version lacks some desktop features such as advanced call controls.

After applying these fixes, Teams should remain signed in across restarts and future updates. To prevent the problem from recurring, check your Windows update settings and pause updates during critical work periods. Also, set up a recurring reminder to clear the Teams cache every few months.