

Newell said developing processes for the PlayStation 3 was "a waste of everybody's time" and "a disaster on many levels. In 2007, Newell expressed his displeasure over developing software for game consoles. By 2011, Steam controlled 50–70% of the market for downloaded PC games and generated most of Valve's revenue. During the production of Half-Life 2 (2004), Newell spent several months developing Steam, a digital distribution service for games.

Harrington left in 2000, leaving Newell as the sole owner. They funded development of the first Valve product, the first-person shooter Half-Life (1998), and its GoldSrc game engine. Inspired by Michael Abrash, who left Microsoft to work on the game Quake at id Software, Newell and another employee, Mike Harrington, left Microsoft to found Valve in 1996. Newell later said he learned more during his first three months at Microsoft than he ever did at Harvard, which was one of the primary reasons why he dropped out. He also led development on a port of the 1993 first-person shooter game Doom for Windows 95 the port is credited for helping make Windows a viable game platform. He spent the next 13 years working there, serving as a producer of the first three releases of the Windows operating systems. He enrolled at Harvard University in 1980 but dropped out to work for Microsoft in 1983. Newell attended Davis Senior High School in Davis, California.
