Ubuntu 12.04 LTS Precise Pangolin released few days ago. If you are using Ubuntu 10.04 LTS Lucid Lynx or Ubuntu 11.10 Oneiric Ocelot, you can upgrade to Ubuntu 12.04 LTS Precise Pangolin without installing from scratch. There are two methods we can use, upgrading via Internet or upgrading via alternate Ubuntu CD (without Internet connection).

1. Upgrading with Internet connection
Ubuntu users who have high speed Internet access can upgrade to Ubuntu 12.04 LTS Precise Pangolin easily by typing the following command on Linux Terminal:

  • update-manager -d
The Update Manager window will appear and inform that New Ubuntu release '12.04 LTS' is available. All you need to do is just click the "Upgrade" button.

2. Upgrading without Internet connection
Well, if you have slow Internet connection, you might want to try upgrading to Ubuntu 12.04 LTS Precise Pangolin using alternate install CD. The alternate install CD allows you to perform certain specialist installations of Ubuntu. It provides for the following situations:
  • setting up automated deployments
  • upgrading from older installations without network access
  • LVM and/or RAID partitioning
  • installs on systems with less than about 384MiB of RAM (although note that low-memory systems may not be able to run a full desktop environment reasonably).
Download Ubuntu 12.04 LTS Precise Pangolin alternate installer CD

There is an install script inside the alternate installer CD, just execute it to perform the upgrade.

Regards :)