its tesco, are you surprised?
apparantly they run common garden XP pro and yes they are networked, how the F do you think the NFC and visa card payment works, pixie dust and sneakernet?
Or how else do ALL the tills recieve any price changes to the stores portfolio on a daily basis? RS232 and a clown with a laptop? pfft no.
Allegedy they were replacing all with new EPOS from NCR then they had to divert the millions to the gaping hole in their pension pot. ;o) I personally wouldnt give Tesco steam off my techy excrement, "loyalty" card anyone?
Oh and others ive spotted, Home bargains until recently used W95 based POS ;) beat that! :P