How can I fix a 404 Error using a PPA?
I can't remove the red triangle in the right upper corner of my desktop. When I type
sudo apt-get update && sudo apt-get upgrade
I get the error message below:
W: Failed to fetch http://ppa.launchpad.net/michael-gruz/canon/ubuntu/dists/precise/main/source/Sources 404 Not Found W: Failed to fetch http://ppa.launchpad.net/michael-gruz/canon/ubuntu/dists/precise/main/binary-i386/Packages 404 Not Found E: Some index files failed to download. They have been ignored, or old ones used instead.
How to fix my problem?