Microsoft unveiled on Monday an upgrade to its mobile operating system as the US software giant seeks to regain lost ground in the competitive handset market, according to an AFP report. Windows Mobile 7 was made public on the first day of the Mobile World Congress in Barcelona, Spain, ending months of speculation about what Microsoft had in store for the industry’s biggest trade show. The new system, which follows the launch of Windows Mobile 6.5 in October, is “a major new step in our strategy,” Nicolas Petit, director of Microsoft’s mobile division in France, told AFP. “It is a total break from what we were doing before,” Petit said. Microsoft completely changed the platform’s interface, with a “dynamic screen” allowing users to install his or her favourite icon, from music, to contacts and social networks, he said. It was inspired by the design of Zune, the Microsoft MP3 player that is only available in the United States at the moment.