“I switched from Office to LibreOffice “
I still carry around my MS Office 2003 disc, and hold on to it like grim death. When we move, in my carry-in is my jewelry, important papers, Office 2003, and flash drive with my recipes.
I use both OpenOffice and LibreOffice, but have an old MS 2000 Excel disc. Never used it (nor know how).
LibreOffice will handle just about any MS documents except the Access Database - old docs can be saved in various Office formats, the Libre Format, or PDF - it even maintains most spreadsheet formulas if you have sheets set up to do math functions.