At the moment I have a 3.1 kernel installed from elsewhere and the regular 3.0.12 (upgraded to 3.0.13 today) kernel from the repos. When booting up, GRUB will choose 3.1 by default. I want it to choose 3.0.12/13 by default. How can I make it do that?
/etc/default/grub with your favorite text editor, ie
sudo nano /etc/default/grub
Locate the line
Change it to the line you want to boot from default, to see which line you want press the key Shift right after your computer computer's POST and keep it pressed, Grub will show the lines available to boot, the fist one is 0, the 2nd one is 1, etc. Insert the value you want in
I liked Bruno's suggestion but all my secondary options were under a "Previous Linux versions" submenu, so I wasn't 100% sure how that would affect the numbering, and I'd prefer a GUI option if there is one.
Firstly, do not use StartUp-Manager (
startupmanager), it is no longer maintained and according to reviews in the Software Center no longer works.
Once installed, run it and select Preferences. In the first tab (General) there is an option for defaults. "Previous Linux versions" are marked 4 > 1, 4 > 2 and so on. Select the one you want.