What to Know An XLSX file is a Microsoft Excel Open XML Format Spreadsheet file. Open one with Excel, Excel Viewer, Google Sheets, or another spreadsheet program.

Under the File name field, change the extension from ‘.xlsx’ to ‘.xls’ and save it. Try opening the file again. 2] Use the Open and Repair feature in Excel ...

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 ...