Windows To Go is a Microsoft Windows 8 Enterprise tool that allows users to boot Windows 8 with a USB thumb or external hard drive on compatible host PC’s.
Windows To Go is a type of Bring Your Own Computer (BYOC) technology that enables a user to initiate a Windows 8 instance on the go.
Techopedia explains Windows To Go
Windows To Go is primarily an enterprise solution available on only Windows 8 Enterprise edition. It enables the creation of Windows 8 Enterprise and Windows 8 Pro 32 and 64 bit edition instances on portable USB storage media having at least 20 GB of storage capacity. The instances can only be created on USB 3.0 devices but can be plugged into USB 2.0 port. The instances provides almost all the functionality and services as of a typical Windows 8 installation however some features are disabled such as hibernate mode, Recovery Environment and utilizing host PC’s internal hard drives. Moreover, Windows To Go is not supported on ARM processors or on Windows RT.
This definition was written in the context of Windows 8