Warning. The Linux kernel is a critical element of the system. To do the upgrade costs when one of your hardware devices is not working properly, and the new kernel may fix this problem. But at the same time installing a new kernel unnecessarily can lead to undesirable regressions, such as: no network connection, no sound or even the inability to boot the system, so install a new kernel on your own risk.
sudo apt-add-repository -y ppa:teejee2008/ppa sudo apt-get update sudo apt-get install ukuu
If you decide to delete the kernel 4.12,
1. When the computer boots, the GRUB menu, select your old kernel. After booting the system, remove the new kernel by command below
2. Use program UKUU or command:
3. And update GRUB or BURG
sudo apt purge linux-image-4.12-*
To return to the previous kernel when booting Grub select Previous Linux versions