Summary

This article covers what to do when Microsoft Teams refuses to open at all — you click the icon and nothing happens, the app briefly flashes and disappears, or it never gets past the splash screen. This is different from Teams opening but showing a blank screen (see Related Articles) or Teams opening but failing to sign in. The steps below address stuck processes, corrupted cache, credential conflicts, and broken installations.

Symptoms

• Teams won't open no matter how many times you click the icon — nothing appears on screen.
• Teams starts but sits stuck on the loading or spinning screen and never reaches your chats.

In this guide

• 1. Check If Teams Is Already Running in the Background
• 2. Try the Teams Web App
• 3. Clear the Teams Cache
• 4. Clear Stored Credentials
• 5. Repair or Reset Teams via Windows Settings
• 6. Check for Windows Updates
• 7. Reinstall Teams
• 8. Re-register the Teams App (New Teams Only)
• 9. Check if Antivirus or Firewall Is Blocking Teams
• 10. When to Contact IT

Before You Start

• A Microsoft 365 account with a Teams license.
• An active internet connection (verify by opening a web page in your browser).
• Windows 10 or Windows 11.

Instructions

1. Check If Teams Is Already Running in the Background

Teams may already be running as a hidden background process. When this happens, clicking the icon does nothing because Windows thinks the app is already open.

1. Press Ctrl + Shift + Esc to open Task Manager.
2. Look for Microsoft Teams in the process list. There may be multiple entries.
3. Click each Microsoft Teams entry and click End task.
4. After ending all Teams processes, try launching Teams again from the Start menu or taskbar.
5. If Teams opens normally, the issue was a stuck background process. If Teams now opens but crawls or freezes once you are in, follow How to Fix Slow or Unresponsive Microsoft Teams instead — this guide is for when it will not open at all. If it still does not open, continue to Step 2.

2. Try the Teams Web App

Before spending time troubleshooting the desktop app, confirm that your account and license are working.

1. Open your browser and go to https://teams.microsoft.com.
2. Sign in with your work credentials.
3. If the web version loads and works correctly, the problem is specific to the desktop app on your computer — continue with the steps below.
4. If the web version also does not work, the issue may be with your account, license, or a service outage. Check https://status.office.com for known outages before continuing.

3. Clear the Teams Cache

Corrupted cache files are the single most common reason Teams fails to launch. Clearing the cache forces Teams to rebuild everything from scratch. The condensed steps are below — for the dedicated walkthrough, follow How to Clear the Microsoft Teams Cache.

1. End all Teams processes in Task Manager (Step 1).
2. Press Win + R to open the Run dialog.
3. Type the path for your version of Teams and press Enter:
   • New Teams (Teams 2.x): %localappdata%\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams
   • Classic Teams: %appdata%\Microsoft\Teams
4. Select all files and folders inside this directory and delete them.
5. Try launching Teams again. You will need to sign in again.

4. Clear Stored Credentials

Windows keeps its own copy of your sign-in details, and that copy can go stale.

Old or conflicting credentials stored in Windows Credential Manager can prevent Teams from starting, especially if you have recently changed your password or switched organizations.

1. Press the Start key, type Credential Manager, and press Enter.
2. Click Windows Credentials.
3. Look for any entries that contain:
   • msteams
   • teams
   • login.microsoftonline.com
   • office.com
4. Click each matching entry and select Remove.
5. Close Credential Manager.
6. Try launching Teams. You will be prompted to sign in fresh.

5. Repair or Reset Teams via Windows Settings

Windows has built-in tools to repair or reset store-installed apps without a full uninstall.

1. Press Win + I to open Settings.
2. Navigate to Apps > Installed apps.
3. Search for Microsoft Teams and click the … (three dots) next to it.
4. Select Advanced options.
5. Scroll down and click Repair first. This fixes common issues without removing your data. Wait for the process to complete.
6. Try launching Teams.
7. If Repair did not help, go back to Advanced options and click Reset. This clears all local Teams data — equivalent to a clean install.
8. Try launching Teams again. You will need to sign in.

6. Check for Windows Updates

Teams depends on Windows components (especially WebView2) that are updated through Windows Update. A pending update can cause compatibility issues.

1. Press Win + I to open Settings.
2. Navigate to Windows Update.
3. Click Check for updates.
4. Install any available updates and restart your computer if prompted.
5. After restarting, try launching Teams.

7. Reinstall Teams

If the steps above have not resolved the issue, a clean reinstall replaces all app files and ensures you have the latest version.

1. Press Win + I to open Settings.
2. Navigate to Apps > Installed apps.
3. Find Microsoft Teams, click the … (three dots), and select Uninstall.
4. After uninstallation, clear any remaining cache files (see Step 3) to ensure nothing is left behind. No messages or files live in the cache — they are on Microsoft's servers, and a fresh install downloads them again when you sign in. That is why clearing it is safe and why it fixes the problem.
5. Restart your computer.
6. Download the latest version from https://teams.microsoft.com/download and install it.
7. Open Teams and sign in with your work credentials.

8. Re-register the Teams App (New Teams Only)

If New Teams was pre-installed by Windows and has become corrupted at the system level, re-registering the app package can fix it without a full reinstall.

1. Press the Start key, type PowerShell, and press Enter.
2. Type the following command and press Enter:

Get-AppxPackage -Name MSTeams | Reset-AppxPackage

3. Wait for the command to complete (it may take 30 seconds).
4. Try launching Teams from the Start menu.

9. Check if Antivirus or Firewall Is Blocking Teams

Security software occasionally blocks Teams from launching — especially after a Teams or antivirus update.

1. Temporarily disable your antivirus software (look for a "Pause protection" or "Disable real-time scanning" option in the antivirus app's settings).
2. Try launching Teams.
3. If Teams opens successfully, the antivirus was blocking it. Add an exception for Teams in your antivirus settings:
   • New Teams: %localappdata%\Packages\MSTeams_8wekyb3d8bbwe
   • Classic Teams: %localappdata%\Microsoft\Teams\current\Teams.exe
4. Re-enable your antivirus protection immediately after adding the exception.

10. When to Contact IT

Whether the fault sits on this PC or on your account decides who fixes it, so answer that in the ticket. State whether https://teams.microsoft.com works in a browser, whether Teams runs on your phone, and copy any Conditional Access or device compliance message you saw.

Contact your IT helpdesk if:

• You have completed all steps above and Teams still does not open.
• The Teams web app (https://teams.microsoft.com) also does not work — this may indicate a licensing issue or account restriction.
• You receive errors about Conditional Access, device compliance, or your organization's policies when trying to launch Teams.
• Teams opens on other devices (phone, another computer) but not on this machine — IT may need to inspect device-specific policies.
• Your organization recently migrated to New Teams and the Classic version was removed, but New Teams fails to install or launch.

Troubleshooting

DANGER

If Teams works in the browser (https://teams.microsoft.com) but not as a desktop app, the problem is local to your computer. Start with ending background processes (Step 1) and clearing the cache (Step 3) — together, these resolve the majority of launch failures.

Symptom / Error	Potential Cause	Solution
Click Teams icon, nothing happens	Background process blocking new instance	End all Teams processes in Task Manager (Step 1).
Splash screen appears, then app closes	Corrupted cache data	Clear the Teams cache (Step 3).
Teams crashes immediately after password change	Stale credentials in Credential Manager	Clear stored credentials (Step 4).
Teams worked yesterday, not today	Cache corruption or pending update	Clear cache (Step 3), check for Windows updates (Step 6).
Meeting links open in browser instead of app	Teams desktop app not registered	Reinstall Teams (Step 7) or re-register the app (Step 8).
"This app can't open" error	Corrupted app package (New Teams)	Reset via Settings (Step 5) or re-register (Step 8).
Teams opens on other computers but not this one	Local configuration or policy issue	Repair/Reset (Step 5), then reinstall (Step 7). If it persists, ask IT to check whether a device-specific policy is blocking Teams on this machine.
Teams blocked by security software	Antivirus or firewall interference	Temporarily disable antivirus to test (Step 9). Add an exception if confirmed.

Related Articles

• How to Fix Microsoft Teams Showing a Blank or White Screen
• How to Troubleshoot Teams Login and Sync Issues
• How to Fix Slow or Unresponsive Microsoft Teams
• How to Clear the Microsoft Teams Cache
• How to Troubleshoot Apps That Won't Open or Keep Crashing on Windows
• How to Fix Common Computer Glitches by Restarting

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