In K-12, almost everybody goes to local schools. Universities are a bit different because kids actually do pick the university. The bizarre thing, though, is that the merit of university is actually how good the students going in are: the SAT scores of the kids going in.

The only thing I understand deeply, because in my teens I was thinking about it, and every year of my life, is software. So I'll never be hands-on on anything except software.

I really do think cancer will largely be a solved problem. I think most of the infectious diseases like malaria - our foundation is very involved - once we're finishing polio eradication, then starting up this malaria eradication, and getting that done as fast as we can.

The common thread for everything I do is this idea of a Web-services architecture. What does that mean? It means taking components of software and systems and having them be self-describing, so that you can aim them, ask them what their capabilities are, and communicate with them using a standard protocol.

I believe it’s not only possible to eradicate malaria; I believe it’s necessary. Ultimately, the cost of controlling it endlessly is not sustainable. The only way to stop this disease is to end it forever.

As we get robots becoming more sophisticated, I think we should worry sooner rather than later on how much they could take over, but I think it'll mostly be a positive thing. In terms of deadlines it won't be any worse than nuclear weapons.

Windows is probably the most important product in the entire PC industry. Everything we do in terms of supporting touch, new hardware, accessibility has incredible impact.