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.

Using Dynamic Arrays to List Files. Excel’s dynamic arrays feature takes the functionality of the FILES function to the next level. When you enter the named formula containing the FILES function ...

Using the file history method, you can easily restore an Excel file to a previous version. If you have an Excel file from a hard drive that you want to restore, you can use the workbook feature.

2] Use the Open With option. Another attempt you can make to open the file in Excel when Notepad is trying to read it is to use the Open With option.