Ubgrade ubuntu from 7.04 feisty

[tellar]

I am using Ubuntu Server 7.04 and I want to upgrade but I get the following errors.

How can I upgrade?

MY DISTRIBUTION:
Distributor ID: Ubuntu
Description: Ubuntu 7.04
Release: 7.04
Codename: feisty

Errors:

apt-get update

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

(I have read that this vesion is no longer supported)

do-release-upgrade

Checking for a new ubuntu release
Failed Upgrade tool signature
Failed Upgrade tool
Done downloading
extracting '/tmp/tmpdgzTPI/gutsy.tar.gz'
Traceback (most recent call last):
File "/usr/bin/do-release-upgrade", line 45, in <module>
fetcher.run()
File "/usr/lib/python2.5/site-packages/UpdateManager/Core/DistUpgradeFetcherCore.py", line 160, in run
if not self.extractDistUpgrader():
File "/usr/lib/python2.5/site-packages/UpdateManager/Core/DistUpgradeFetcherCore.py", line 98, in extractDistUpgrader
tar = tarfile.open(self.tmpdir+"/"+os.path.basename(self.uri),"r")
File "/usr/lib/python2.5/tarfile.py", line 1139, in open
return func(name, "r", fileobj)
File "/usr/lib/python2.5/tarfile.py", line 1200, in gzopen
fileobj = file(name, mode + "b")
IOError: [Errno 2] No such file or directory: '/tmp/tmpdgzTPI/gutsy.tar.gz'

[falko]

I guess the problem is that Feisty is too old. I guess the repositories don't exist anymore...