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 you receive Microsoft Excel cannot access the file, There are several possible reasons error message you can use the following suggestions to resolve the issue.

File-security limits can curtail your ability to open or save Microsoft Excel files.

If you have a spreadsheet from Works versions 6 and later, you can open it directly in Excel. If you used an even older version, you can re-save the file as an Excel formatted file from within Works.