something like this one
Private Sub ComboBox1_Change()
 Application.ScreenUpdating = False
     If UCase(ComboBox1.Value) = "YES" Then
        Rows("10:15").Hidden = True
    ElseIf UCase(ComboBox1.Value) = "NO" Then
        Rows("10:15").Hidden = False
    End If
        Application.ScreenUpdating = True
End Sub