Warning: This will reset all pinned applications

• Paste the following into a .bat file and double click it

  DEL /F /S /Q /A "%AppData%\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\*"
  
  REG DELETE HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Taskband /F
  
  taskkill /f /im explorer.exe
  
  start explorer.exe

Navigate to

%userprofile%\AppData\Local

and delete IconCache.db