On Jan. 21, Microsoft revealed many of the major features coming to Windows 10. Two days later, Microsoft released an updated Windows 10 Technical Preview. The Technical Previews have been made available to the public, but are meant only for testing purposes, and will not completely reflect what Windows 10 will be like in its final form. The latest version, Build 9926, does not include some of the things that Microsoft showed off on the 21st, including deep integration of Skype into the OS, and the new Spartan web browser. But there are many important features in this build. Here's a closer look.