Bork!Bork!Bork! Things must be tough for UK grocery retailer Sainsbury's, judging by the state of Windows Activation on one of its self-service kiosks. "Unexpected item in the bagging area" are words to strike fear into any shopper. After all, the flashing red light atop the kiosk is not always enough to attract the attention of a bored member of staff, slouching nearby, and the queue behind you is just getting longer. However, an "Activate Windows" watermark is an altogether more alarming message. Register reader Mark Powell found Windows whinging about activation at his local Sainsbury's store. He spotted the watermark of shame in the bottom right-hand corner, atop the retailer's application. Powell asked, "I wonder how many 40p bags you'd need to buy to get a Windows license?" The message appears when Windows decides it is unlicensed. This might be caused by skipping the product key during installation, or by a hardware change triggering the operating system into a deactivated state.…