Windows Phone 7
Windows Phone 7 was the first release of the Windows Phone mobile client operating system, released worldwide on October 21, 2010, and in the United States on November 8, 2010. It received multiple large updates, the last being Windows Phone 7.8, which was released in January 2013. It added a few features backported from Windows Phone 8, such as a more customizable start screen.Microsoft ended support for Windows Phone 7 on October 14, 2014. It was succeeded by Windows Phone 8, which was released on October 29, 2012.