@kaia #ZorinOS feels like a cross between #Windows10 and #Windows11, but I don't know of a #Linux distro that looks like #WindowsXP specifically. I think #WINE should be able to run #Office365 tax software, but if not, most #Microsoft apps should be able to run in the cloud if that's what he's using.
Alternatively, running #WindowsXP alongside #Malwarebytes might not be a terrible option.