What operating system did the Nokia Lumia 800 use at launch?

The Nokia Lumia 800 used Windows Phone at launch, specifically Windows Phone 7.5 “Mango.” It was Nokia’s first smartphone to run Microsoft’s mobile operating system.

Nokia unveiled the Lumia 800 on October 26, 2011, at Nokia World. The phone was part of Nokia’s new partnership with Microsoft, announced earlier that year, and represented a major shift away from Nokia’s established Symbian platform. The device was launched in Europe in November 2011.

The Lumia 800’s design closely resembled the MeeGo-powered Nokia N9, which causes a common mix-up. The two phones shared a polycarbonate body and curved AMOLED display, but their internal hardware and software were different. The Lumia 800 ran Windows Phone 7.5, while the N9 ran MeeGo.

The phone included Nokia-specific services such as Nokia Drive, Nokia Maps, and Nokia Music. It later received Windows Phone 7.8, but it could not be upgraded to Windows Phone 8 because of major platform and kernel changes.