Techradar posted a tutorial about crating an USB install stick for Windows 7

Reinstalling Windows isn't always a walk in the park. It can take a lot of time and this is the main reason why many of us put it off for as long as possible. It could quite easily take all day to install updates and drivers, let alone all your favourite applications. However, with the help of a program called RT7Lite you can create a faster custom installation of Windows that suits you.

  Tutorial: How to create a USB Windows 7 install stick