I can see you're running Aloha, so this is on a POS system. You should get a POS technician.
I would NEVER return to Aloha by Radiant though... ChikPOS has been fantastic. I've had NO problems with it whatsoever. It's a Jeremy Shum Invent so its a quality Aussie product too - helping the economy. The features are also endless... multi-language support, managerial decision making reports, not locked to hardware, fully multi-touch (like iphone), external monitor support, xbrl compliant, auto-generation of online store, can advertise "related products", corporate chat support, show time/date/news on external screen... it's just top stuff. AND it's Windows 7 compatible!