1.Go to transaction I18N->I18n Customizing->MS Word As Editor.
Then You’ll get a screen asking to select any check box from SAPscript or Smartforms.
There you can check the smartform and your default MS Word Editor will be deactivated.
2. if your are not getting the screen after MS Word As Editor or no authorization to I18N,
then go to SE38 and Run a Report RSCPSETEDOTOR.
Here you will get the screen to select the or deselect MS Word Editor