"Any view that the innovation [at Microsoft] comes primary from me reflects the notion that there has been an overfocus of my contribution," Gates said. "From Office, Windows, SQL Server, Exchange and Xbox -- I am not the primary person on any of those things."

As for his role after July 2008, Gates said, "I am not leaving Microsoft. I am here working as hard as I ever have over the next two years."

He went on to add: "I don't see a time in the future where I won't be the chairman of the company. I want to have that association my entire life."

Gates said he made the transition announcement now to send a clear message that "this transition is a very serious thing, [and] it is starting now." In addition, Gates said he and Microsoft CEO Steve Ballmer have gone "carefully through the things I actually do -- not what is written -- and how those will be taken on."

Ballmer stressed that the company "is ready and capable of making a smooth and orderly transition to a new set of technical leaders without missing a beat.