Download the latest from here:

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

The folders correspond to kernel versions and should also include the ubuntu version, for example I chose to update 11.10 (oneiric) from “3.0.0-14-generic” to “3.1.4″, this was in a directory called “v3.1.4-oneiric/“.

You’ll need 3 files (replace * with the kernel version you’ve downloaded):

linux-headers-*_all.deb

For 64 bit systems (replace * with the kernel version you’ve downloaded):

linux-headers-*_amd64.deb
linux-image-*_amd64.deb

For 32 bit systems (replace * with the kernel version you’ve downloaded):

linux-headers-*_i386.deb
linux-image-*_i386.deb

Once you have the files, install them in the following order using these commands (of course, replacing the version number for the ones you’ve downloaded):

Once that’s done, reboot. Once you’re back use the following command to check that the kernel you’re using is the one you’ve just downloaded and installed!