>>no reson
>>only the customers start using it
>>so what can you do
>
>You should explain to them that if they want to use very old software they shouldn't expect it to run on the newest OS.

Sometimes, business just buys a new computer without an option to select OS, or at least nobody cares about this option until it's delievered and software stops to work. It may open some market for converting old programs, btw.