If you are running older versions of Ubuntu, such as 10.10, and wish to upgrade the kernel from the mainline kernel repository, you will quickly find out that the precise kernels work, but the quantal kernels do not.
Installing a quantal kernel will appear to go smoothly until you try to install the linux-headers-3.4.2____amd64.deb file (for a 64-bit system). The Ubuntu Software Center will refuse to proceed due to a dependency error with libc6.
The quantal kernel requires libc6 version 2.14 or higher, but Ubuntu 10.10 only has libc6 version 2.12.1. libc6 is a tough program to upgrade since it is considered an essential component of Linux and protected by Synaptic.
If you find yourself in the situation of an incomplete kernel update, it might be easier to undo the incomplete installation and revert to the previous kernel. To do this, open Synaptic Package Manager (System > Administration > Synaptic Package Manager) and enter 3.4.2 in the Quick Search box. This displays a list of all 3.4.2 related files that have been installed so far.
All 3.4.2 kernel files must be removed. To uninstall each 3.4.2 file, mark each one for complete removal (right-click the file and choose Mark for Complete Removal) and click Apply. If you have upgraded GRUB, then open a terminal and update GRUB2 again so the previous kernel will be loaded upon the next boot.
This technique will remove any kernel from your system, not just 3.4.2. Always remember to run sudo update-grub after removing the files.