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.

If Excel is not opening on double-click or not responding on your Windows 11/10 PC, take a look at the addons first, or else follow these suggestions to resolve the issue.

If Microsoft Excel fails to recognize a file in the XLSX or XLS format, the data contained in the file could be corrupted. When you open a corrupted workbook in Excel, the program should ...