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 ...

How to Open an XLS File in Excel. XLS files are Excel workbook files created in Excel 97 or Excel 2003. The 2007, 2010 and 2013 versions of the program use the XLSX format by default to save ...

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.

Designed for use with Office 2000, XP, and 2003, the downloadable add-on allows you to open, edit, and save the newer file formats, seamlessly converting the files on the fly and in the background.

Can OpenOffice Run Excel?. In the free open-source office suite Apache OpenOffice, Calc is the spreadsheet equivalent to Microsoft Excel. Calc allows you to open and edit files originally saved in ...