If you launch multiple files by double-clicking their shortcut icons, or via the "Open" menu in Excel, the files will run simultaneously in one Excel window.

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 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.

An Excel Workbook 2007 or 2010 business file enhanced with macros will have the XLSM file extension. If you have Excel 2007 or 2010, double-click the filename to open the file.