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.

How to Open Excel 2007 Files As Separate Windows. If you work with multiple Excel files over the course of a workday, and especially if you use a dual-monitor setup, you might wonder how you can ...

If you cannot open an Excel file and see Excel cannot open the file because the file format or extension is not valid error, see this post.

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 ...

While it is technically possible to open an Excel file in Notepad, this is not a good idea. Excel files are binary files that contain complex formatting and data structures. When you open an Excel ...