How to update Ubuntu 12.04

First thing you should do just after the installation is updating the Ubuntu. Ubuntu 12.04 is the LST version and would be supported until April 2017. If you have Ubuntu 12.04 freshly installed, very first thing after installation is to update all the repositories. This would save you from unmet dependency errors.
In this article we would update Ubuntu. Open software center.

From edit click on software source

Under Ubuntu Software tab, enable all the repositories except source code and click on download from

Select other from download drop down

Now click on select best server

You need to authenticate this with super user password. Super user account is the user account which we create during the installation.

Ubuntu will perform several testing to select best server for your location.

Once Ubuntu select best server for you click on chose server

Now click on other software tab. whenever you install any software via PPA it makes its entry here in this list.
PPAs (Personal Package Archive) are repositories. You can use PPAs to install or upgrade packages that are not available in the official Ubuntu repositories. One of the most common causes of unmet dependencies is PPAs, especially when used to upgrade the existing package in Ubuntu repositories. To solve the problem you have three options, disable, purge (revert back to original package in Ubuntu repositories) or remove PPA. All these options are available here.
If it is a fresh installation you will get only four options here. Enable canonical partners. And click on close.

That all setting we need to in software center.
Now press ALT + CTRL+T key combination to open the terminal and run following command

 sudo apt-get clean
 

This command would clears out the local repository of retrieved package files (the .deb files). It removes everything but the lock file from /var/cache/apt/archives/ and /var/cache/apt/archives/partial/. This is very helpful especially when you are facing unmet dependency errors.
Now run following command.

sudo apt-get -f install
 

The -f here stands for "fix broken". Apt will attempt to correct broken dependencies. If you manually installed a package that had unmet dependencies, apt-get will install those dependencies, if possible, otherwise it may simply remove the package that you installed in order to resolve the problem.

Now run following command

sudo apt-get update
 

This command would update the repository. Any change which you have made in software source from Ubuntu software center will also take place.
Now run following command

sudo apt-get upgrade
 

This command would update the Ubuntu. This will ensure that you will get the latest Ubuntu. On a fresh installation it is going to take a lot of times. During the upgrading process you need to confirm several actions.

After upgrading reboot the system.
After reboot you have latest Ubuntu. Check our other articles to explore Ubuntu.