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 workbooks, but can also use the XLS format.

How to Open XLS Files on a Smartphone. XLS is the default file type for Microsoft Office Excel files. It is compatible with nearly all programs that read spreadsheet files. If you are looking to ...

Excel displays a warning message that the file format and extension don’t match (HTML table and XLS), but allows the user to open the file anyway. Today, users reported that these reports no ...

Here's how Open your file in Excel. From the Office tab, select Save As., In the new dialog box select your preferred file type, such as cvs or txt and click OK. You will receive a warning that (your ...

Please ensure the .xls file is not opened in other workbooks, add-ins, or apps. After coming to that conclusion, simply attempt to open the file again in Excel to see if the problem no longer exists.