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 ...

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 ...

After the MS16-088 patch is applied, though, Excel refuses to open XLS files, showing a blank screen instead of a workbook. Poster conker123 on the TechNet Office forum described the problem ...

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.