Error Message in Natty Narwhal Update Manager

http://ppa.launchpad.net/akirad/akirad/ubuntu/dists/

The PPA doesn't have a natty branch. You should remove the PPA. It is no good to you now

I am using Natty Narwhal and have been told "The PPA doesn't have a natty branch. You should remove the PPA." I do not know how to remove the PPA. Can someone tell me how to remove the PPA.

Use software centre. You don't need to repeat the above post.

This is not answering my question. I went to the software center and installed ppa-purge. I then went into terminal mode and typed:

sudo ppa-purge

but I still get the same error message.

I need more explicit guidance to resolve my problem. Cryptic comments are not helpful.

you need to use the ppa address in ppa-purge, running ppa-purge without a repository address does nothing

If you also run:

sudo add-apt-repository ppa:cinelerra-ppa/ppa; sudo apt-get update; sudo apt-get upgrade

You now have a Natty repo for the same app.

With all due respect you are NOT responsive to my question. You persist in giving me cryptic replies. You tell me running ppa-purge with a repository address does nothing. I figured that out myself. I do not know what my "repository address" is. I cannot figure out what to put in from this error message:

W:Failed to fetch http://ppa.launchpad.net/akirad/akirad/ubuntu/dists/natty/main/binary-amd64/Packages 404 Not Found
, W:Failed to fetch http://ppa.launchpad.net/akirad/ppa/ubuntu/dists/natty/main/binary-amd64/Packages 404 Not Found
, E:Some index files failed to download. They have been ignored, or old ones used instead.

I see that you, actionparsnip, continue to respond to my question. Can you refer me to someone who is more helpful?

ok can you give the output of:

ls /etc/apt/sources.list.d

Thanks

Yes. Here is the output:

akirad.list
google-earth.list.distUpgrade
natty-partner.list
akirad.list.distUpgrade
google-talkplugin.list
google-earth.list
google-talkplugin.list.distUpgrade

Thanks actionparsnip, that solved my question.