After enabling the Client Hyper-V feature on a Windows 8-based computer, the computer may hang while booting. This may also occur after installing the Windows Phone 8 SDK due to it's dependency on installing the Client Hyper-V feature.
This problem occurs on computers with GIGABYTE motherboards, and has USB 3.0 host controllers enabled in the BIOS.
Update the BIOS/Firmware of the computer to the latest supported release by GIGABYTE.
For additional troubleshooting steps related to the installation of the Windows Phone 8 SDK, see this following article: