Speaking at The Venture Forum (http://www.theventureforum.com/) conference, Microsoft's Bryan Barnett, a program manager for external research programs in the Microsoft Research group, said multicore architectures are of particular interest when weighing what to put in future operating systems at the company.

"Taking full advantage of the processing power that those multicore architectures potentially make available requires operating systems and development tools that don't exist largely today," Barnett said

Windows currently will run on multicore processors, but is not fully optimized for them, according to Barnett. "It's not a question of just running on a multicore architecture. It's a question of what do you do to fully exploit the capabilities there," he said.

There is no timetable for a Windows successor right now. But early work on this effort has not yet been organized, with five or six small projects afoot in various places throughout the company, said Barnett.

Finding a DOS successor in the early 1990s seemed a simpler task, he said. "Somehow, it was easier when the company was smaller a long time ago," Barnett said.