I have shown you how to update to the latest Windows 10 preview build 9926. The new build was released by Microsoft on Jan 23, 2015 which bring Cortana to Windows 10 desktop. The latest build also introduces new Start menu and user interface, directory icons on the Windows Explorer, new Settings interface and more.
This post shows you some cool Windows 10 Pro Technical Preview screenshots running on my old Compaq Presario CQ42.
New Windows 10 Expanded Start menu
New Icons on Windows Explorer
New Windows 10 Notifications