This post will give you solution to to Upgrade From Ubuntu 11.04 to 11.10 (Oneiric Ocelot)
Features of Ubuntu (Oneiric Ocelot)1.As of now Firefox releases its version 5, Ubuntu 11.10 comes with this Firefox 5.
2.It comes with upgraded Linux Kernel 3.0-rc5 and gcc 4.6.1 compiler.
3.Mozilla Thunderbird will be the standard Email client for Oneiric Ocelot.
4.GNOME 3 is now the default desktop environment, with Unity on top of it.
5.Ubuntu 11.10 will comes with a backup tool called Deja Dup by default, which will allow users to easily backup and restore their important files.
6.In place of gdm, lightdm will be the login manager.
7.The default umask for users who have a private user group was changed from 022 to 002, which makes it a lot easier to share data between trusted users by putting other users into the private user group.
Type ” update-manager -d ” into the command box and hit in “Run“.
Now Update Manager will open up and tell you that New distribution release ’11.10′ is available. Click Upgrade and follow the on-screen instructions to successfully install the Ubuntu 11.10
How to Upgrade From Ubuntu 11.04 to 11.10 (Oneiric Ocelot)