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I am still using 10.10 because I have had no reason to upgrade. At this point, I need some of the newer packages so I need to upgrade. I tried upgrading to 11.04 (the only version that update manager gives me...) and it fails with this:
W:Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/main/source/Sources.gz 404 Not Found , W:Failed to fetch http://extras.ubuntu.com/ubuntu/dists/natty/main/binary-amd64/Packages.gz 404 Not Found , E:Some index files failed to download, they have been ignored, or old ones used instead.
Please help me.