Possible Duplicate:
How can I fix a 404 Error using a PPA?
Failed to download repository information
Check your Internet connection.
W:Failed to fetch http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu/dists/quantal/main/source/Sources 404 Not Found,
W:Failed to fetch http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu/dists/quantal/main/binary-i386/Packages 404 Not Found,
E:Some index files failed to download. They have been ignored, or old ones used instead
My internet connection works well.
What are this updates and why it fails?