Problems updating packages..

Firstly hello to everyone,

I am in no way very skilled when it comes to the Linux system, but appreciate the system very much.

I have been having a problem for some time now, when I try to update on the packages screen.

All looks good first of all, system looks like its trying to update, as you can see the bar moving along, but then the problem begins.

A message comes back, which is as follows:

Failed to fetch http://security.ubuntu.com/ubuntu/dists/karmic-security/main/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://security.ubuntu.com/ubuntu/dists/karmic-security/restricted/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://security.ubuntu.com/ubuntu/dists/karmic-security/universe/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic/main/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic/restricted/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic/universe/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic/multiverse/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic-updates/main/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic-updates/restricted/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic-updates/universe/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://security.ubuntu.com/ubuntu/dists/karmic-security/multiverse/binary-i386/Packages.gz 404 Not Found [IP: ]

Failed to fetch http://archive.ubuntu.com/ubuntu/dists/karmic-updates/multiverse/binary-i386/Packages.gz 404 Not Found [IP: ]

Some index files failed to download, they have been ignored, or old ones used instead.

I therefore close this screen down, and come out of the updates page. Then along the task bar at the bottom of the screen, to the right (ish) hand side, it tells me that I'm upto date..

If anyone can help me with this issue, I would be truely grateful. I warn you now though, please keep any help to a basic level, as I am not the most computer knowledged.

Many thanks & One Love.