Ribbon Disabler will allow you to disable Ribbon in Windows 8 Explorer and preserve Paint and Wordpad working. Aslo it has an option to restore ribbon.
Ribbon Disabler command line options
Ribbon disabler.exe /d – delete the ribbon silently
Ribbon disabler.exe /r – restore the ribbon silently
For Windows 8 x64:
Ribbon disabler x64.exe /d – delete the ribbon silently
Ribbon disabler x64.exe /r – restore the ribbon silently
Ribbon Disabler is portable application and does not require to be installed.
Download Ribbon Disabler for Windows 8
You can download Ribbon Disabler for Windows 8 from here