ActiveWorkbook.Close SaveChanges:=False 

Public WithEvents app As Excel.Application

Private Sub App_WorkbookBeforeClose(ByVal Wb As Workbook, _
  Cancel As Boolean)
    Wb.Close SaveChanges:=False
End Sub

Dim a As New EventClassModule

Public Sub Auto_Open()
    Set a.app = Application
End Sub

Public WithEvents app As Excel.Application
Private col As New Collection

Private Sub app_WorkbookBeforeClose(ByVal Wb As Workbook, _
  Cancel As Boolean)
    Dim intI As Integer
    Dim strWbName As String
    Dim fChanged As Boolean
    
    On Error Resume Next
    
    strWbName = Wb.Name
    
    For intI =  1  To col.Count
        If col.Item(intI) = strWbName Then
            MsgBox "Данные изменены."
            fChanged = True
            Exit For
        End If
    Next intI
    
    If Not fChanged Then
        Wb.Close SaveChanges:=False
    End If
    
    col.Remove strWbName
End Sub

Private Sub app_SheetChange(ByVal Sh As Object, _
  ByVal Source As Range)
    On Error Resume Next
    
    col.Add Sh.Parent.Name, Sh.Parent.Name
End Sub