Unable to Open Start Menu & Receiving Error 5fcl8 When Signing In to Microsoft Office

Overview

This guide applies when the Windows Start Menu does not open at all.

This issue may also occur alongside Error 5fcl8 when signing in to Microsoft Office 365.

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Steps

1. Open Command Prompt (CMD) as Administrator.

2. Paste and run the following command:
   reg delete "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Notifications" /va /f

   The Start Menu should immediately begin working after this step.

3. If the issue persists, open Registry Editor (Regedit).

   

4. Navigate to:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\

   

5. Delete the Notifications key.
6. Restart the computer.
7. Retry using the Start Menu and signing in to Microsoft Office 365.