I updated Ubuntu 10.04 and now it auto-boots to the new kernel. I want to boot an older kernel but the boot menu is missing?
Hold down shift when starting your computer, and keep holding it until you see the grub menu. This will prevent it from booting automatically.
You can also permanently make the menu show. I'm using 12.04 so I can't check, but you should be able to find a file /boot/grub/grub.conf with a timeout option. You can set it to something like 10 seconds, which will display the menu for 10 seconds before booting automatically. Edit it with
and then run
to apply the changes and try rebooting.
While booting, keep the