This article provides the information on "Systems equipped with the Intel Skylake CPU and chipsets are no longer equipped with legacy USB 2.0 hub".
The new Skylake CPU and chipsets have removed the legacy USB 2.0 hub. The main effect of this hardware change is the inability to install Windows 7 from a USB flash drive due to Windows 7 not having native USB 3.0 driver support.
This may also affect installation of Ubuntu Linux.
Installation of Windows 7/Ubuntu on these systems can be accomplished from DVD and from Preboot eXecution Environment (PXE) network imaging.
There may also be problems with installing Ubuntu from flash drives. The main tools for creating a Linux USB installer this are PenDrive Linux, Yumi, and Rufus. None of these tools currently work with Skylake based systems.