Re: XP Home Edition!
Thanks for the reminder regarding supermarkets...
The "self checkout" stations at our regional hypermarket** chain also run XP, I think (or possibly something even older like 2000; could have just been an NT / 2000-like theme). Not sure about the staffed checkouts.
** Hypermarket: full supermarket + department store. More food and less merch than a (former glory) Kmart, and regional, not national like Walmart.