If you run into problems with your PC, a USB
recovery drive can help you troubleshoot and fix those problems, even if
your PC won't start.
Your PC might have come with a recovery image
that’s used to refresh or reset your PC. The recovery image is stored on
a dedicated recovery partition on your PC, and is typically 3-6 GB in
size. To save space on your PC, you can delete the recovery image from
your PC and use a recovery drive instead. Windows 8.1
includes a built-in tool to create a USB recovery drive. Windows will
let you know how big the recovery partition is, and you'll need a USB
flash drive at least that big.

