In an effort to use my printer, I installed a PPA but in the end, this PPA was not necessary. Now, this PPA causes an error when updates are loaded. The update error message is the following:
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.
I looked over the web how to remove a ppa but the answers are too technical for my level of understanding. I found this line:
sudo add-apt-repository --remove ppa:whatever/ppa
but I don't know what should be put in place of the "whatever". On top of that, I can't even remember how I installed this PPA. I know I went to this page:
and somehow, followed the included instructions, without really knowing what I was doing.
According to some help pages I found, installed file in /etc/apt/sources.list.d should give me some hints:
jockey.list nvbn-rm-ppa-precise.list langdalepl-gvfs-mtp-precise.list nvbn-rm-ppa-precise.list.save langdalepl-gvfs-mtp-precise.list.save precise-partner.list michael-gruz-canon-precise.list precise-partner.list.save
but I don't understand what to look for in this list of files. I suspect that the culprits is michael-gruz-canon-precise.list, but that doesn't help me much.
I hope I put all the necessary info here.
Thank you for your help