Today during the press Q&A after the Chrome OS/Chromebook keynote, Google co-founder Sergey Brin joined the panel to share his thoughts on the new products and Google in general. Since the end goal of Chrome OS is clearly to end Windows dominance both in the workplace and the world in general, someone asked what percentage of Google employees still use Windows machines at work?

“I’d probably guess 20 percent,” Brin said in response. “But I’d have to get back to you,” he quickly qualified noting that he doesn’t have the exact numbers.

Still, unless his guess is way off, that’s equally surprising and impressive. Windows is, after all, still the OS that dominates the world — and businesses in particular. But apparently not Google — at all.

Brin also noted that of Windows users, there are very few not using Windows 7, the latest version of Microsoft’s OS. And he quickly followed up that there’s nothing inherently wrong with the OS, and that Windows 7 has some great security features.

Still, what Google is doing with Chrome OS is trying to rebuild the model from the ground up. This makes it not only a challenge to Microsoft, but anyone else in the OS space. “The complexity of managing your computers is torturing users out there. All of us,” Brin said. “That’s a flawed model fundamentally. Chromebooks are a new model,” he continued.

Brin also said that since Google will be deploying Chromebooks internally, he hopes that a year from now, there will only be a small percentage of Googlers not working on the devices.