friends PC is unable to login, they get an error about the login failing, something along the lines of the login service failed, its the only account on his PC, he does not have a repair disc and does not want to mess with the new install in case of wiping his data, would taking my HDD around and using that to login and move his data to an external HDD to back them up, be a viable means or would it not function, we both use Win 7