Affichage + de 1 millions de lignes

Sub Nettoie() 'Laurent Longre mpfe, mise en forme GeeDee
Dim Sht As Worksheet, DCell As Range, Calc As Long, Rien As String,
Avant As Double, plage As Range
On Error Resume Next
Calc = Application.Calculation ' ---- mémorisation de l'état de recalcul
'------------------------------------------------------------
MsgBox "Pour le classeur actif  : " _
& Chr(10) & ActiveWorkbook.FullName _
& Chr(10) & "dans chaque feuille de calcul" _
& Chr(10) & "recherche la zone contenant des données," _
& Chr(10) & "réinitialise la dernière cellule utilisée" _
& Chr(10) & "et optimise la taille du fichier Excel", _
vbInformation, _
"d'après LL par GeeDee@m6net.fr"
'-------------------------------------------------------------
MsgBox "Taille initiale de ce classeur en octets" _
& Chr(10) & FileLen(ActiveWorkbook.FullName), _
vbInformation, ActiveWorkbook.FullName
'------------------------------------------------------------
With Application
.Calculation = xlCalculationManual
.StatusBar = "Nettoyage en cours..."
.EnableCancelKey = xlErrorHandler
.ScreenUpdating = True
End With
'-------------------- le traitement
For Each Sht In Worksheets
Avant = Sht.UsedRange.Cells.Count
Application.StatusBar = Sht.Name & "-" & Sht.UsedRange.Address
'-------------------Traitement de la zone trouvée
If Sht.UsedRange.Address <> "$A$1" Or Not IsEmpty(Sht.[A1]) Then
Set DCell = Sht.Cells.Find(What:="*", _
                   LookIn:=xlFormulas, _
                SearchOrder:=xlByRows, _
         SearchDirection:=xlPrevious)(2)
'----------------Suppression des lignes inutilisées
If Not DCell Is Nothing Then
Sht.Range(DCell, Sht.Cells([A:A].Count, 1)).EntireRow.Delete
Set DCell = Nothing
Set DCell = Sht.Cells.Find(What:="*", _
                   LookIn:=xlFormulas, _
                SearchOrder:=xlByColumns, _
         SearchDirection:=xlPrevious)(2)
'----------------Suppression des colonnes inutilisées
If Not DCell Is Nothing Then Sht.Range(DCell, Sht.[IV1]).EntireColumn.Delete
End If
Rien = Sht.UsedRange.Address
End If
ActiveWorkbook.Save
'---------------------Message pour la feuille traitée
MsgBox "Nom de la feuille de calcul :" _
& Chr(10) & Sht.Name _
& Chr(10) & Format(Sht.UsedRange.Cells.Count / Avant, "0.00%") &  _
" de la taille initiale", vbInformation, ActiveWorkbook.FullName
Next Sht
'--------------------Message fin de traitement
MsgBox "Taille optimisée de ce classeur en octets " & Chr(10) & _
FileLen(ActiveWorkbook.FullName), _
vbInformation, _
ActiveWorkbook.FullNameActive
'--------------------
Application.StatusBar = False
Application.Calculation = Calc
End Sub