This month's monster security patch for Office breaks Excel when it tries to open HTML files, and it seems unlikely Microsoft will fix the problem Excel users are reporting an odd bug in the way ...

If your XLSX file isn’t opening in Excel, you might not have Excel 2007 or a later version, which is needed for XLSX compatibility. Ensure your Microsoft Excel is updated.

You can also have Excel open automatically. Disable Start screen and automatically open a blank Excel workbook By default, a Start screen appears when you open Excel (see the screenshot below). The ...