In this post we’ll mention all the steps which are necessary for the upgrading 12.04 LTS Desktop to 14.04 LTS.
By default the update manager will not show the 14.04 release until July when the 14.0.1 version is release. So you need to do this manually.
Backup your Data:
It is always necessary to backup all the data so if there is an issue you cannot lose your data. Backup your data to external drive or some Flash drive.
You need to open the Update-Manager application from dash board and must verify that you install all the updates which are listed.
You can also do this through terminal, ctrl+alt+t to open terminal and type the following commands:
sudo apt-get update
sudo apt-get update-manager-core
Then write the command “sudo update-manager -d” and press enter, it asks for the password, enter your password. The update manager will open and prompt to upgrade, click the button to start the process.
After restating the new Ubuntu 14.04 is on your system and you can enjoy the release.
For verification write command: