Fix Outlook Authentication Loop Error – Microsoft Account 2SV Issues 2026

This method clears corrupted authentication tokens that cause login loops.

1. Press Windows + R, type control, and press Enter
2. Navigate to User Accounts → Credential Manager
3. Click Windows Credentials tab
4. Locate all entries containing "Microsoft Office", "Outlook", or your Microsoft account email
5. Click each entry and select Remove
6. Close Control Panel and open File Explorer
7. Navigate to %LOCALAPPDATA%\Microsoft\Outlook
8. Delete all .ost and .pst files (backup important emails first)
9. Open Outlook and enter your credentials when prompted
10. Complete the two-step verification process with a working method

Access your Microsoft account through alternative verification methods to update security info.

1. Open a web browser and navigate to account.microsoft.com
2. Click Sign in and enter your email address
3. When prompted for password, click Forgot my password
4. Select I forgot my password and click Next
5. Choose an alternative verification method (backup email, security questions, or Authenticator app)
6. If using Authenticator app, open Microsoft Authenticator on your phone
7. Tap the account and enter the displayed code
8. Once signed in, go to Security → Security dashboard
9. Click Update info next to "Ways we can contact you"
10. Add a new phone number or email address for verification
11. Remove old, inaccessible verification methods
12. Test the new verification method by signing out and back in

Create a new Outlook profile to eliminate authentication corruption.

1. Close Outlook completely
2. Press Windows + R, type appwiz.cpl, and press Enter
3. Right-click Microsoft Office and select Change
4. Choose Quick Repair and click Repair
5. After repair completes, press Windows + R, type control mlcfg32.cpl, and press Enter
6. Click Show Profiles
7. Click Add to create a new profile
8. Enter a profile name (e.g., "Outlook2026") and click OK
9. In the Add Account wizard, enter your email address
10. Click Advanced options and check Let me set up my account manually
11. Select Office 365 and click Connect
12. Complete the modern authentication flow with two-step verification
13. Set the new profile as default in Mail Setup dialog
14. Delete the old corrupted profile

Clear authentication tokens using PowerShell commands for advanced troubleshooting.

1. Press Windows + X and select Windows PowerShell (Admin)
2. Run the following command to clear cached credentials:

Get-StoredCredential | Where-Object {$_.Target -like "*microsoft*" -or $_.Target -like "*office*" -or $_.Target -like "*outlook*"} | Remove-StoredCredential

3. Clear Windows Authentication cache:

klist purge

4. Reset the Windows Credential Manager service:

Stop-Service -Name "VaultSvc" -Force
Start-Service -Name "VaultSvc"

5. Clear Office authentication cache:

Remove-Item -Path "$env:LOCALAPPDATA\Microsoft\Office\16.0\Wef\*" -Recurse -Force -ErrorAction SilentlyContinue

6. Reset network authentication:

netsh winsock reset
netsh int ip reset

7. Restart the computer to apply all changes
8. Open Outlook and re-authenticate with your Microsoft account

Create an app-specific password to bypass two-step verification issues in Outlook.

1. Sign in to your Microsoft account at account.microsoft.com
2. Navigate to Security → Security dashboard
3. Under Advanced security options, click App passwords
4. Click Create a new app password
5. Enter "Outlook Desktop" as the app name
6. Click Generate and copy the generated password
7. Open Outlook and go to File → Account Settings → Account Settings
8. Select your Microsoft account and click Change
9. In the password field, paste the app-specific password
10. Uncheck Remember password if it causes issues
11. Click Next and Finish
12. Test email synchronization