I installed a new version of Ubuntu (11.04), but I really hate it; version 10 was much better.
Is it possible to downgrade somehow? If so, how?
Alternatively should I just remove Ubuntu and install the old version again?
52 Answers
To formalize this: Yes, it is possible, but no, you don't want to do that.
The main reason is that when you're upgrading, you might change configuration files with upgrade scripts. There are no downgrade scripts, so an older version of a package might not work with your configuration anymore. It's safer to reinstall and migrate your data back.
If you want to do it, Ask Ubuntu's got you covered there: Downgrade from one version to a previous version?.
If you're just annoyed by the design, which is called "Unity", you can disable it in 11.04. On your login screen, select Ubuntu Classic Desktop instead of Ubuntu Desktop Edition.
Note that in future Ubuntu versions, there will be no classic desktop anymore, so you'll have to live with Unity. If you want to configure it, there are plenty of options though.
Another idea would be to install another desktop manager, like changing to GNOME 3.
4I used so-called "apt-pinning" in my case to downgrade from mixed-version Ubuntu to lucid:
$ cat /etc/apt/preferences.d/downgrade-to-lucid Package: * Pin: release a=lucid Pin-Priority: 1010 Package: * Pin: release a=lucid-updates Pin-Priority: 1011 Package: * Pin: release a=lucid-security Pin-Priority: 1012 
