I've just got a fresh server running Ubuntu 14.10 in a data center. I tried to install FTP with sudo apt-get install vsftpd this gave me an error that it couldn't fetch and it told me to run sudo apt-get update. So I tried to do that and then I got the following error message.
csvuser@k2521s002:~$ sudo apt-get update
Ign http://security.ubuntu.com utopic-security InRelease
Ign http://archive.ubuntu.com utopic InRelease
Ign http://security.ubuntu.com utopic-security Release.gpg
Ign http://archive.ubuntu.com utopic-updates InRelease
Ign http://security.ubuntu.com utopic-security Release
Ign http://archive.ubuntu.com utopic Release.gpg
Ign http://archive.ubuntu.com utopic-updates Release.gpg
Ign http://archive.ubuntu.com utopic Release
Ign http://security.ubuntu.com utopic-security/main amd64 Packages/DiffIndex
Ign http://archive.ubuntu.com utopic-updates Release
Ign http://security.ubuntu.com utopic-security/universe amd64 Packages/DiffIndex
Ign http://archive.ubuntu.com utopic/main amd64 Packages/DiffIndex
Ign http://archive.ubuntu.com utopic/universe amd64 Packages/DiffIndex
Ign http://archive.ubuntu.com utopic-updates/main amd64 Packages/DiffIndex
Ign http://archive.ubuntu.com utopic-updates/universe amd64 Packages/DiffIndex
Err http://security.ubuntu.com utopic-security/main Sources
404 Not Found [IP: 91.189.91.13 80]
Err http://security.ubuntu.com utopic-security/universe Sources
404 Not Found [IP: 91.189.91.13 80]
Ign http://security.ubuntu.com utopic-security/main Translation-en_US
Ign http://security.ubuntu.com utopic-security/main Translation-en
Ign http://security.ubuntu.com utopic-security/universe Translation-en_US
Ign http://security.ubuntu.com utopic-security/universe Translation-en
Err http://security.ubuntu.com utopic-security/main amd64 Packages
404 Not Found [IP: 91.189.91.13 80]
Err http://security.ubuntu.com utopic-security/universe amd64 Packages
404 Not Found [IP: 91.189.91.13 80]
Err http://archive.ubuntu.com utopic/main Sources
404 Not Found [IP: 91.189.91.24 80]
Err http://archive.ubuntu.com utopic/universe Sources
404 Not Found [IP: 91.189.91.24 80]
Ign http://archive.ubuntu.com utopic/main Translation-en_US
Ign http://archive.ubuntu.com utopic/main Translation-en
Ign http://archive.ubuntu.com utopic/universe Translation-en_US
Ign http://archive.ubuntu.com utopic/universe Translation-en
Err http://archive.ubuntu.com utopic-updates/main Sources
404 Not Found [IP: 91.189.91.24 80]
Err http://archive.ubuntu.com utopic-updates/universe Sources
404 Not Found [IP: 91.189.91.24 80]
Ign http://archive.ubuntu.com utopic-updates/main Translation-en_US
Ign http://archive.ubuntu.com utopic-updates/main Translation-en
Ign http://archive.ubuntu.com utopic-updates/universe Translation-en_US
Ign http://archive.ubuntu.com utopic-updates/universe Translation-en
Err http://archive.ubuntu.com utopic/main amd64 Packages
404 Not Found [IP: 91.189.91.24 80]
Err http://archive.ubuntu.com utopic/universe amd64 Packages
404 Not Found [IP: 91.189.91.24 80]
Err http://archive.ubuntu.com utopic-updates/main amd64 Packages
404 Not Found [IP: 91.189.91.24 80]
Err http://archive.ubuntu.com utopic-updates/universe amd64 Packages
404 Not Found [IP: 91.189.91.24 80]
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/main/source/Sources 404 Not Found [IP: 91.189.91.13 80]
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/universe/source/Sources 404 Not Found [IP: 91.189.91.13 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/utopic/main/source/Sources 404 Not Found [IP: 91.189.91.24 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/utopic/universe/source/Sources 404 Not Found [IP: 91.189.91.24 80]
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/main/binary-amd64/Packages 404 Not Found [IP: 91.189.91.13 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/utopic-updates/main/source/Sources 404 Not Found [IP: 91.189.91.24 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/utopic-updates/universe/source/Sources 404 Not Found [IP: 91.189.91.24 80]
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/utopic-security/universe/binary-amd64/Packages 404 Not Found [IP: 91.189.91.13 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/utopic/main/binary-amd64/Packages 404 Not Found [IP: 91.189.91.24 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/utopic/universe/binary-amd64/Packages 404 Not Found [IP: 91.189.91.24 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/utopic-updates/main/binary-amd64/Packages 404 Not Found [IP: 91.189.91.24 80]
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/utopic-updates/universe/binary-amd64/Packages 404 Not Found [IP: 91.189.91.24 80]
E: Some index files failed to download. They have been ignored, or old ones used instead.I did some research but couldn't really find a solution. Thanks!
EDIT 1:
Everything I try to install gives me this
404 Not Found [IP: 91.189.88.149 80]
error. It can't find certain files on the ubuntu website.
You may want to edit /etc/apt/sources.list and replace all occurances of "archive." or "security." in the defined URLs by "old-archives." - then run sudo apt-get update and it should work fine.