git pull: permission denied

I created a repository in my desktop and push to github, then clone that repository to my laptop to make development, later committed the changes and push to github. now back to my desktop, i tried 'git pull' to get all the changed i made, it showed the error message: Permission denied (publickey) fatal: The remote end hung up unexpectedly.

how could this happen? i push the repository to github originally from my desktop it know the remote, now it complained p开发者_如何学编程ermission denied?

Your best bet is to go to your github account and make sure both your desktop AND your laptop's public keys are there and available. This page may also help you out: http://help.github.com/troubleshooting-ssh/