The larger a spreadsheet gets, the more likely you'll want to start hiding rows or columns or maybe you've been given a sheet that has hidden rows or columns.

If you have sensitive data you'd like to keep from prying eyes in a Microsoft Excel file, the easiest way to protect it is with Excel's built-in password tools.

You worked hard to put that Excel sheet together, now protect it from unintended damage.

14. To make all cells editable again, click on "Unprotect Sheet" — which is in the "Protect" tab under "Review" — and re-enter your password. The cells will now be unlocked.