Belfiore also showed how Internet Explorer 11 has been updated so it can be used to view and render legacy websites, a feature called "enterprise mode," aimed primarily at companies with old intranets that their employees still need to access with, for example, IE 8.
He clarified that these new mouse-and-keyboard features haven't been added at the expense of the touchscreen functionality already present in the OS since its Windows 8 initial release, which all remain.
Microsoft also gave a quick peek at the much-awaited "touch first" version of its Office suite for the tile-based Modern interface in Windows 8 and 8.1 devices, which ironically will arrive after the version for iPads, launched last week.
Kirk Koenigsbauer, a corporate vice president with the Office team, showed a pre-release version of PowerPoint for touchscreens, highlighting that the "ribbon" menus are consistent with the desktop version of the suite, but optimized for touch.
As Microsoft develops this "touch first" version, it wants to make sure the applications provide an "unmistakably Office experience" across devices of all sizes, such as small tablets and large touch-enabled screens, he said.
In addition to replicating the "ribbon," that means replicating advanced features, capabilities and elements in the applications, like inserted pictures and graphics in Word and "inking" in PowerPoint that lets presenters circle things in slides on the fly.
He didn't say when this "touch first" version of Office will be ready.
Juan Carlos Perez covers enterprise communication/collaboration suites, operating systems, browsers and general technology breaking news for The IDG News Service. Follow Juan on Twitter at @JuanCPerezIDG.