VBA compter cellules au demarrage

Option Explicit
Private Sub Workbook_Open()
    Dim i As Long, compteur As Double
    With Application: .ScreenUpdating = False: .Calculation = xlManual: .EnableEvents = False: End With
    Sheets("Feuil1").Activate ' nom onglet adapter
    compteur = 0
    For i = Cells(Rows.Count, "f").End(xlUp).Row To 3 Step -1
        If Range("f" & i) <> Range("g" & i) And Range("g" & i) <> "" Then compteur = compteur + 1
    Next i
    MsgBox compteur
    With Application: .EnableEvents = True: .Calculation = xlAutomatic: .ScreenUpdating = True: End With
End Sub

MsgBox compteur

MsgBox "Vous avez " & compteur & " faute(s) !"

Sub NombreErreurs()
Application.ScreenUpdating = False
Dim rng As Range: Set rng = Range("H3:H3000")
rng = "=IF(AND(RC[-2]<>RC[-1],RC[-1]<>""""),""$"",0)"
MsgBox "Vous avez " & Application.CountIf(rng, "$") & " faute(s).", vbCritical
Columns(8).ClearContents
Application.ScreenUpdating = True
End Sub

Sub Oups()
  Dim R As Range, n As Long
  Set R = Range("H3:H" & [A6500].End(xlUp).Row): R.FormulaLocal = "=(F3=G3)+(G3<>0)"
  n = Application.CountIf(R, 1)
  MsgBox "Vous avez " & n & " faute" & IIf(n < 2, "", "s"), , "": R.Clear
End Sub

MsgBox "Vous avez " & n & " faute" & Chr(32 + 83 * Sgn(n - 1))

Private Sub Workbook_Open()
With Sheets("Feuil1").[G3:G3000] 'plage adaptable
MsgBox "Vous avez " & _
Evaluate("SUM((" & .Columns(0).Address & "<>" & .Address & ")*(" & .Address & "<>""""))") _
& " faute(s) !"
End With
End Sub