You don't necessarily need Microsoft Excel to work with an .xlsx file Reviewed by Ryan Perian This article explains what XLSX files are, how to open them, and which programs are able to convert ...

If your Excel files are opening in Notepad on Windows PC, here's how you can reset the settings to make .xls, .xlsx, etc files open in Excel.

How to edit .xlsx files on Mac So, how do you edit an .xlsx file on a Mac? Due to the open file format used by Microsoft’s Excel software, it’s surprisingly easy to edit a .xlsx file on a Mac.