Option Explicit
Sub TheInsertor()
Dim Cell As Range, Plage As Range
Dim Start As Double
Dim Ajout As Byte
Dim nb_ligne_total As Long
Start = Timer
With Worksheets('Sheet2')
nb_ligne_total = .Range('A65536').End(xlUp).Row
Set Plage = .Range(.Cells(3, 1), .Cells(nb_ligne_total, 1))
Ajout = 0
For Each Cell In Plage
If .Cells(Cell.Row, 1).Value <> .Cells(Cell.Row + 1, 1).Value And Ajout = 0 Then
With .Cells(Cell.Row + 1, 1).EntireRow
.Insert
.Interior.ColorIndex = 0
.Borders.LineStyle = 0
End With
Ajout = 1
Else
Ajout = 0
End If
Next
End With
MsgBox Timer - Start
End Sub