reg add HKCU\Software\Microsoft\Office\12.0\Excel\Options /v DefaultFormat /t REG_DWORD /d 51 /f

reg delete HKCU\SOFTWARE\Microsoft\Office\12.0\PowerPoint\Options /v DefaultFormat /f

reg add HKCU\Software\Microsoft\Office\12.0\Word\Options /v DefaultFormat /t REG_SZ /d "" /f