If the System32 folder shows on the desktop, there may be an invalid entry in the Registry
  1. Start Regedit
  2. Go to both:
  3. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  4. HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
  5. Double check that the values do not have incorrect, incomplete, or blank entries