Gates said he's not satisfied with the company's innovations.
Microsoft founder and chairman, Bill Gates, said the company's early strategy in mobile phones was a mistake.
Speaking to CBS, Gates said he's not satisfied with the company's innovations.
When asked if he was happy with the company's chief executive officer, Steve Ballmer's performance, Gates said, "Well, he and I are two of the most self-critical people -- you can imagine. And here were a lot of amazing things that Steve's leadership got done with the company in the last year."
"Windows 8 is key to the future, the Surface computer. Bing, people are seeing it as a better search product, Xbox," Gates said.
"But is -- is it enough? No, he and I are not satisfied that in terms of, you know, breakthrough things, that we're doing everything possible."
"We didn't miss cell phones, but the way that we went about it didn't allow us to get the leadership. So it's clearly a mistake."
Ballmer was appointed as Microsoft's CEO in February 2000 and the company's shares have been reportedly dropped 45% since his appointment.
Microsoft reported revenue of $21.46bn for the fiscal second quarter of 2013 ended 31 December 2012, compared to $20.88bn it reported during the same period in 2011.