Disable new Right-click context menu
reg.exe add "HKCU\Software\Classes\CLSID{86ca1aa0-34aa-4e8b-a509-50c905bae2a2}\InprocServer32" /f /ve
Disable new Explorer command bar layout
reg.exe add "HKCU\Software\Classes\CLSID{d93ed569-3b3e-4bff-8355-3c44f6a52bb5}\InprocServer32" /f /ve
Note:
Restarting your users Explorer.exe process is required for the changes to take effect (or a restart if you prefer).