Insert blank rows in a large data series

This will do it:

Sub foo()
    Dim l As Long
    For l = Cells(Rows.Count, 1).End(xlUp).Row To 2 Step -1
        Cells(l, 1).Offset(1, 0).Resize(2).EntireRow.Insert
    Next l
End Sub

Activate the worksheet where you want to insert blank rows.

Press Alt-F11 to open the Visual Basic Editor.

Click Insert > Module. In the module which appears, paste the code from post #2.

Click File > Close and return to Microsoft Excel.

Press Alt-F8 to open the Macro dialog.

Select macro "foo" then click Run.


Done.

Yes, to insert 3 blank rows, change the 'resize' value:

        Cells(l, 1).Offset(1, 0).Resize(3).EntireRow.Insert