Private Sub Worksheet_Change(ByVal Target As Range)

If Target.Address = "$E$2" And Range("D2").Value = "" Then
  Application.EnableEvents = False
  Target.Value = ""
  Application.EnableEvents = True
End If

End Sub

Private Sub Worksheet_Change(ByVal Target As Range)

If Not Intersect(Target, Range("E2")) Is Nothing And Range("D2").Value = "" Then
  Application.EnableEvents = False
  Range("E2").Value = ""
  Application.EnableEvents = True
End If

End Sub

Private Sub Worksheet_Change(ByVal Target As Range)

If Not Intersect(Target, Range("E2")) Is Nothing And Range("D2").Value = "" Then
  Application.EnableEvents = False
  Range("E2").Value = ""
  Application.EnableEvents = True
  MsgBox "Текст вставлю сам", vbCritical, "Ошибка ввода данных"
End If

End Sub

Private Sub Worksheet_Change(ByVal t As Range)

Dim b As Boolean
Application.EnableEvents = False
CheckCol t, "E"
CheckCol t, "G"
CheckCol t, "W"
CheckCol t, "AA"
Application.EnableEvents = True

End Sub

Private Sub CheckCol(t As Range, col As string)

Set t = Intersect(t, Columns(col), Me.UsedRange)
If Not t Is Nothing Then
  For Each t In t
    If Not IsEmpty(t) Then
      If IsEmpty(t.Offset(, -1)) Then t.ClearContents: b = True
    End If
  Next
  If b Then MsgBox "Текст вставлю сам", vbCritical, "Ошибка ввода данных"
End If

End Sub

Private Sub Worksheet_Change(ByVal t As Range)

Application.EnableEvents = False
CheckCol t, "E"
CheckCol t, "G"
CheckCol t, "W"
CheckCol t, "AA"
Application.EnableEvents = True

End Sub

Private Sub CheckCol(t As Range, col As string)

Dim b As Boolean
Set t = Intersect(t, Columns(col), Me.UsedRange)
If Not t Is Nothing Then
  For Each t In t
    If Not IsEmpty(t) Then
      If IsEmpty(t.Offset(, -1)) Then t.ClearContents: b = True
    End If
  Next
  If b Then MsgBox "Текст вставлю сам", vbCritical, "Ошибка ввода данных"
End If

End Sub