Possible Duplicate:
How can I fix a 404 Error using a PPA?
When i try to check updates comes
W:Failed to fetch http://ppa.launchpad.net/kayo-k11-4/nv-switcheroo/ubuntu/dists/oneiric/main/source/Sources 404 Not Found
W:Failed to fetch http://ppa.launchpad.net/kayo-k11-4/nv-switcheroo/ubuntu/dists/oneiric/main/binary-i386/Packages 404 Not Found
E:Some index files failed to download. They have been ignored, or old ones used instead.
What i must do?