| Comment | You may remove the 3.5 kernel by using ppa-purge 1) Install ppa-purge sudo apt-get install ppa-purge 2) Remove the ppa sudo ppa-purge ppa:ubuntu-x-swat/q-lts-backport 3) PPA Purge will find the packages installed and offered to downgrade them. Say yes and ppa-purge will remove the upgraded versions and reinstall the versions from the archive. 4) Remove the meta packages sudo apt-get remove --purge linux-image-generic-lts-quantal linux-headers-generic-lts-quantal 5) Remove the kernel itself. While running the new kernel, enter the following command uname -r This returns a number, like '3.5.0-8-generic'. Use the number (3.5.0-8) to replace the word KERNEL sudo apt-get remove --purge linux-image-KERNEL-generic linux-headers-KERNEL linux-headers-KERNEL-generic sudo apt-get autoremove Eg, for '3.5.0-8' sudo apt-get remove --purge linux-image-3.5.0-8-generic linux-headers-3.5.0-8 linux-headers-3.5.0-8 |