This question already has an answer here:
Whenever I execute sudo apt-get update I get this error message:
W: Failed to fetch http://ppa.launchpad.net/jolicloud-team/ppa/ubuntu/dists/natty/main/source/Sources 404 Not Found E: Some index files failed to download. They have been ignored, or old ones used instead.
I've checked my /etc/apt/sources.list file, but there is no reference to http://ppa.launchpad.net/jolicloud-team . Could anyone help me?