Is it possible to Github and Powershell on a USB drive. And I need it to work just like it would on my computer. Like open the shell through the Github and open the shell from selecting a repository.
You have to use Portable GIT client for windows, here is it's beta version: http://code.google.com/p/msysgit/downloads/detail?name=PortableGit-1.8.0-preview20121022.7z&can=2&q=
Just extract it in your USB drive, now you can use git on any pc without install