The Prince is a regular at the mobile technology show, appearing each year at the British and Scottish stands, as well as visiting other companies at the show to keep abreast of current technology.
However, he appeared confused at a lunch yesterday over why Microsoft was attending the event.
Joy King, director of content marketing solutions at HP, said: "I met Prince Andrew at a lunch and he was very charming, but he was rather confused when he met Microsoft's representative.
"He asked her what she was doing here since this was not a computer show. She had to explain to him for several minutes that Microsoft was also involved in the mobile and handheld space."
King added that the Prince was appalled at the idea of having personalised advertising sent to his mobile phone.
When she discussed operator plans for such a service, he expressed dismay that his personal information could be so closely monitored and that this information could be used to target adverts at him based on his usage patterns.
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