How can I upgrade the Ubuntu LTS kernel to newer?

New deployments of 12.04.2 will be installed with an updated kernel and a new X windows stack. For existing 12.04 deployments, users will need to opt-in to what is being called the LTS Hardware Enablement Stack. If you already have Ubuntu 12.04 installed with an earlier kernel stack, it is recommended that you keep this stack in place rather than switching to a later kernel; the newer kernel and X stacks are provided for enablement of hardware not supported by earlier kernels, and there is generally no reason to upgrade to a newer stack if your hardware is supported by the default kernel.

In order to upgrade to the 3.5 kernel on 12.04.2, you will need to run the following command(s):

For the new kernel:

sudo apt-get install linux-generic-lts-quantal

For the new X stack:

sudo apt-get install xserver-xorg-lts-quantal

WARNING: If you are using the xorg-edgers PPA, do not install the xserver-xorg-lts-quantal package as this will most likely result in breakage.

Reference: https://launchpad.net/~xorg-edgers/+archive/ppa

This is only recommended for x86 hardware installations.

See also:

• The 12.04.2 Release Notes for more details.
• Quantal backported kernel in 12.04.2? What's going on there?
• How to remove Kernel/LTS Enablement Stack?

The simplest set of instructions I always used for kernel upgrade / downgrade are by ubuntuforums.org user by the name of lykwydchykyn (url modified by me for this post):

Go here: http://kernel.ubuntu.com/~kernel-ppa/mainline/ Download 3 (maybe 4) debs to a folder somewhere:

linux-headers-VERSION-NUMBER_all.deb
linux-headers-VERSION-NUMBER_amd64.deb
linux-image-VERSION-NUMBER_amd64.deb
linux-image-extra-VERSION-NUMBER_amd64.deb   # if available

Install the debs with whatever package manager front-end you use (is gdebi still around?), or use these commands:

cd /path/to/folder/where/you/put/the/debs
sudo dpkg -i *.deb

Source: http://ubuntuforums.org/showthread.php?p=11391743#post11391743 and https://askubuntu.com/a/142000/133170

Of course you can install 3.5.0 kernels, run apt-get install linux-image-generic-lts-quantal to install the latest quantal 3.5.0 kernel. This package will ensure that you always have the latest quantal kernel.

I personally recommend raring's 3.8 (base on upstream 3.8.8) kernel anyway.

NOTE: search for available 3.5.0 kernels apt-cache search linux-image-3.5.0.

BTW: You can even manually download latest mainline kernels and install them, for example 3.7.9. However, if you install PPA mainline kernels manually, you'll have to manually install updates.

http://kernel.ubuntu.com/~kernel-ppa/mainline/