Until recently the Apple store registers had been running Windows. From Gizmodo
Since 2005, Apple stores have been ringing up purchases with wireless handheld point-of-sale terminals. This always felt a little odd, partly because you never see a register, but mostly because the devices run Windows. Not anymore!
Apple is in the process of retiring their massive fleet of Windows CE handhelds, made by Symbol Technologies and introduced back in 2005, with custom-designed iPod Touches.