Open the Excel 2010 file that you want to make format changes to. Select the top-left cell in the range of cells that you want to change to the accounting format.

To fix the “Excel file format and extension don’t match” error, first check if the file extension matches its format. Try renaming the file with the correct extension (e.g., .xlsx for Excel ...

To change the default file format for saves in Excel, follow these steps-Open Excel on your computer. Click the File option from the top menu bar. Click on the Options button.