Launch the Registry Editor (hit the Windows key and R, type regedit, and then press Enter) and then navigate to the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\ ImmersiveShell\Launcher
Click Edit > New > DWORD (32-bit) Value, and name it UseExperience.
Double-click the newly created item and set the value to 0.
Click OK, close the Registry Editor and then restart your computer -- or just restart Explorer. (If you can still right-click on your start button, you can use Task Manager to restart Explorer.)