When using Microsoft Internet Explorer, why does Excel not let me rename the worksheet tab?
[Top] When you export to a CSV file, your browser will prompt you to either open the file or save the file. If you select to open the file, Excel will be launched on a temporary file and this causes Excel to get confused about the name of the worksheet tab and it then will not let you rename it. Therefore, when using Internet Explorer, we recommend that you first save the file and then open the file using your worksheet application or a file browser.