You must remove from registry the bellow value: Microsoft Word previewer: HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{84F66100-FF7C-4fb4-B0C0-02CD7FB668FE}  Microsoft Excel previewer: HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{00020827-0000-0000-C000-000000000046}