Possible Duplicate:
How to install software or upgrade from old unsupported release?
Hello all I am fairly new to Ubuntu however I was not able to find an answer to this. I currently run windows 7 through which i run a program called truecrypt. Through Truecrypt i have created a hidden archive and now i am using VMware oracle to run a virtual machine i have two machines one firewalled with damn small linux and the other running Ubuntu 10.10.0 here is my problem although i am currently connected to the internet through this machine when i go to upgrade to current version of Ubuntu I get this message
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-i386/Packages.gz 404 Not Found
E:Some index files failed to download, they have been ignored, or old ones used instead.
needless to say quite a problem seeing as it does not upgrade a prompt response appreciated thank you.