Do you mean the guide gridlines, or the gridlines that
print out? To have your spreadsheet open with the grey
guide gridlines, go to Tools, Options, View, and select
Gridlines. For the printed gridlines, it is better to put
those in yourself after the creation of the spreadsheet -
you don't want every cell outlined throughout the
spreadsheet - that takes up memory, and unless you define
the print area, would print out excess pages.