The latest kernel is causing problems with my sound, which worked fine with an older version. As I have only Ubuntu installed, Grub is not getting displayed while booting. How can I manually choose my kernel version while booting?
The simplest way to display your Grub is to press and hold the SHIFT button while booting.
As an alternative, you can always display Grub without it booting any particular kernel:
gksudo gedit /etc/default/grub
GRUB_TIMEOUT to -1 and comment out
finish off by running
Holding down the shift key while booting, will display the Grub menu. You can now select an older kernel version.
For selecting an older kernel as the default kernel, please see this post
While booting when GRUB appears with entries select the second entry i.e., Advanced options for Ubuntu there you can see different older kernel versions which was installed previously, you can select one among them which works good for you. Otherwise you go to the grub.cfg and paste your required kernel version on top of currently installed kernel entry. In both ways it works
This setting determines how long a screen without the GRUB 2 menu will be displayed. While the screen is blank, the user can press any key to display the menu.
The default behavior is to hide the menu if only one operating system is present. If a user with only Ubuntu wishes to display the menu, place a # symbol at the start of this line to disable the hidden menu feature.
Downgrade Kernel: How to downgrade the Kernel on 11.10
Upgrade kernel: How can I upgrade kernel to 3.1?
If you have a few Kernels in your system you can set manually what Kernel version will start:
Reboot your PC with pressed Shift button for display GRUB after BIOS will start. You will see something like: GRUB start page
Select "Advanced options for Ubuntu" and memorize index of this menu line(count starts from 0) On the picture index is 1
Select concrete kernel for boot and also memorize index of this menu line(count starts from 0) On the picture index of chosen Kernel is 2
Start system. This action is for one boot on concrete kernel. If you want to start from concrete Kernel all time you should do next steps:
4.1. Open and edit GRUB setup file:
sudo nano /etc/default/grub
4.2. Find line GRUB_DEFAULT=...(by default GRUB_DEFAULT=0) and sets in quotes menu path to concrete Kernel(Remember menu indexes from steps 2 and 3). In my system first index was 1 and second was 2. I set in to GRUB_DEFAULT
4.3. Update GRUB information for apply changes:
4.4. After reboot you automatically boot on Kernel by chosen menu path. An example on my machine 1 -> 2
4.5. Check Kernel version after reboot:
Please, install the previous kernel with the following command:
sudo apt-get install linux-image-3.0.0-12-generic linux-headers-3.0.0-12-generic
Then reboot. You will be prompted to choose your kernel.
Let me know if it worked.
I found it simplest to do this using grub-customizer: http://ubuntuhandbook.org/index.php/2014/04/install-grub-customizer-ubuntu-1404/