Private Sub Worksheet_Change(ByVal Target As Range)
Dim a&, mm, aa, zz As Range
If Target.Count > 1 Then Exit Sub
Set zz = Target
If Not Intersect(Columns(2), Target) Is Nothing Then
  With Application
    .EnableEvents = False
    .ScreenUpdating = False
    mm = .Calculation
    .Calculation = xlCalculationManual
    aa = Target.Value
    .Undo
    With Sheets(2)
      a = .UsedRange.Rows.Count
      If Len(.Cells(a, 1)) > 0 Then a = a + 1
      Target.EntireRow.Columns("A:B").Copy .Cells(a, 1)
      .Cells(a, 1).Offset(, 2) = Target.EntireRow.Columns(2) - aa
      .Cells(a, 1).Offset(, 3) = Environ("UserName")
      .Cells(a, 1).Offset(, 4) = Date
      .Cells(a, 1).Offset(, 5) = Time
      With .Range(.Cells(a, 1), .Cells(a, 6))
        .Borders.LineStyle = xlContinuous: .EntireColumn.AutoFit
      End With
    End With
    zz.Value = aa
    .EnableEvents = True
    .ScreenUpdating = True
    .Calculation = mm
  End With
End If
End Sub