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 ...

With Office 2007, Microsoft introduced entirely new file formats for Word, Excel, and PowerPoint. Designated by an x at the end of the file extension (.docx instead of .doc, and so on), these were ...

If the file opens in read-only mode, you may still make changes and use the "Save As" command to save the file to a new name. Save the file in the Excel 2003 or 2007 format, but with a different name.

Enter a name for the new pipe-delimited format file in the "File Name" field. Click the "Save as Type" drop-down list and select the "CSV (Comma Delimited)" option. Click the "Save" button. Excel ...

Starting with Office 2007, Microsoft switched to Office Open XML (OOXML) as the default file formats for its applications. However, the legacy .doc (Word), .xls (Excel) and .ppt (PowerPoint) file ...

Blocking old file formats in the Office 2003 Service Pack 3 (SP3) release was meant to bolster security for Microsoft customers, but whether the new formats are any more secure than older ones is ...

Microsoft has pledged to make its new Office 2007 file formats accessible within the company's other products, but the timeline for that support varies widely. Although the company already has ...

Even though you need a format like 02/08/2021, Excel Online and Google Sheets may use something else, like 08-02-2021. At times, you might not like such a change due to a lack of familiarity.