Sub macro1()
Dim i As Long, j As Long
Application.ScreenUpdating = False
For i = Range("A65536").End(xlUp).Row To 1 Step -1
If Cells(i, 3) <> 0 Then
For j = Cells(i, 3) To 1 Step -1
Rows(i + 1).Insert Shift:=xlDown
Cells(i + 1, 2) = Cells(i, 2) + j
Cells(i + 1, 1) = Cells(i, 1)
Cells(i + 1, 3) = Cells(i, 3)
Next
End If
Next i
Application.ScreenUpdating = True
End Sub