Upgrade of the kernel in Ubuntu Linux

Use the apt-get command to install a newer kernel.

1. First find your kernel version:

    uname -r
   
   

2. Next find available kernel images:

    apt-cache search kernel-image
   
   

3. Now install kernel by explicitly specifying version number:

    sudo apt-get install kernel-image-x.x.x-xx
   
   

Upgrade to a new release

The recommended way to upgrade your Ubuntu servers are through the network, where you can use the server upgrade system.

1. Install update-manager-core:

    sudo apt-get install update-manager-core
   
   

2. Launch the upgrade tool:

    sudo do-release-upgrade
   
   

3. Follow the on-screen instructions

Upgrade to GutsyGibbon Beta

There seems you can only update with a graphically GUI (and you need to be using a user which is allowed to do sudo) by issuing

   update-manager -d

OR follow the howto http://onlyubuntu.blogspot.com/2007/09/upgrade-ubuntu-704-feisty-fawn-to.html which starts out with

   update-manager -c -d

"-c" switch tells it to look for upgrades at all.
"-d" switch means "development"

You can check the ubuntu version installed using the following command

   sudo lsb_release -a