It may appear like Notepad disables and enables Scrollbar's but in reality, it uses 2 different TextBoxes. When you set WordWrap to True, it makes one TextBox visible and the other invisible and vise versa.
Code:
Private Sub mnuWordWrap_Click()
mnuWordWrap.Checked = Not mnuWordWrap.Checked
If mnuWordWrap.Checked = True Then
'If it's checked then make the WordWrap TextBox visible
TextWordWrap.Visible = True
TextNoWordWrap.Visible = False
Else
'If not then make the other one visible
TextWordWrap.Visible = False
TextNoWordWrap.Visible = True
End If
End Sub