方法在这里:
https://help.ubuntu.com/community/HardyUpgrades

ubuntu.cn99.com的源不能用了。这是不好。我这里联它很快的。改用cn.archive那个了。慢！

update 200902: cn99的源重新可以使用了。

这里看都有哪些源可以用： http://wiki.ubuntu.org.cn/index.php?title=Template:6.06sourc...

找了一个，http://ftp.sjtu.edu.cn/ubuntu/ 很快。

Ubuntu 6.06 to Ubuntu 8.04 Upgrade (Server)

I verified that my current install was completely up to date:

sudo aptitude update
sudo aptitude upgrade
sudo aptitude dist-upgrade

http://ubuntu-tutorials.com/2008/04/03/dapper-to-hardy-direc...

Bug #1 in Ubuntu: “Microsoft has a majority market share”
https://launchpad.net/ubuntu/+bug/1

hehe ;)

刚明白ubuntu gnu/linux的版本号是根据发行年份和月份来的。这个命名方式还是很不错的，一目了然知道这个版本有多老了，是不是应该用。

我说呢，这个ubuntu没几年，版本号都6点几了。

我现在用的6.06就是06年6月发布的。我准备用的7.04就是07年4月发布的。哈哈。就是这样。咱们的服务器开始时5.01。我说的6。06是我桌面电脑。

CommonQuestions - Community Ubuntu Documentation
"What is the numbering system of the releases about? What is the next release of Ubuntu?The version number comes from the year and month of the release; the version names are made by [Ubuntu]MarkShuttleworth.Ubuntu 4.10 Warty Warthog was released in October 2004, and was the first ever Ubuntu release.
Ubuntu 5.04 Hoary Hedgehog was released in April 2005.
Ubuntu 5.10 Breezy Badger was released in October 2005.
Ubuntu 6.06 Dapper Drake was released in June 2006; this release saw a delay for technical reasons.
Ubuntu 6.10 Edgy Eft was released in October 2006.
Ubuntu 7.04 (to be) Feisty Fawn, the current development version, is set to be released in April 2007."
https://help.ubuntu.com/community/CommonQuestions