@glnz
All the files should run and install exactly as they are.
It was only the very early versions of .NET that needed modified installers.
I wouldn't worry too much about abandoning XP just yet, even after we stop getting the POSReady updates you should be pretty safe as long as you have another layer of protection from a fully updated anti-malware program.
Strange you should mention seeing that terminal in a hardware store, only today I saw one of the self service tills in my local supermarket doing a disk check, and that said it was XP too. Those tills are quite new NCR units, that were installed way after XP EOS!
Of course they could be running POSReady, which may still look like XP on its on-screen dialogues.