[QUOTE=newdoverman;4257852]Freeze Panes has been around for many versions of Excel. There should be no problem with that aspect of the file. Any new functions not available in the older versions will not work. If you are not using new functions, then no problem unless you are wanting to open xlsx files on versions that supported only xls format (with Excel 2007 this changed to xlsx format).[/QUOTE

Ok, thanks for the quick reply. Now, I have Macros and Goal Seek functions on the file. Which versions do not support those functions, and which versions, besides Excel 2013, supports those functions?