Add Open With to all files

Remove items from the right click of the Start button

HKEY_LOCAL_MACHINE\Software\Classes\Directory\Shell or

HKEY_CLASSES_ROOT\Directory\shell

Double Click Shell and delete any of these sub-keys like DOS Here and Find.

Navigate to:

HKEY_LOCAL_MACHINE\Software\Classes\Folder\Shell or

HKEY_CLASSES_ROOT\Folder\shell

Double Click Shell and delete any of these sub-keys like root explore, open, explore, etc..