downgrading kernel or setting grub default kernel

[chamstar]

I recently allowed update manager to install a new kernel which has broken X, ie. I can only get to command prompt on boot. I have a dual screen setup which took me a fair while to get working.

If I select the old kernel from GRUB everything is okay. Is there any way I can downgrade the kernel back to what it used to be? [Or maybe change the default kernel in GRUB?]

The same thing happened when I upgraded to Hardy, I'm currently on Feisty. When I have time I'll upgrade and get the dual monitors working again but for now I'm happy to stick to Feisty since it works well.

Many thanks, Cham.

[Pumalite]

Maybe all you need with your new kernel is reinstalling your video driver

[chamstar]

Maybe, but I tried for a couple of days to get nvida working with Hardy kernel a few weeks back. I don't have time at the moment to 'play' with it. I use Ubuntu for everyday work as a Ruby programmer. When I get more time I'll get it working, for now I just need to boot to a working kernel Cheers.

[Pumalite]

All you have to do is choose the kernel you want to boot at the Grub menu. Or edit menu.lst and change default=0 for the corresponding number keeping in mind that Grub starts to count from 0.

[sdennie]

An easy way to set the default is to edit /boot/grub/menu.lst:

gksudo gedit /boot/grub/menu.lst

Look for the line towards the top that says "default 0" and change it to "default saved". Then find the line towards the bottom of the huge comment block that says: "# savedefault=false" and change "false" to "true". Save the file and then run:

sudo update-grub

The next time you restart, whatever kernel you choose will be become the default for future restarts.

[chamstar]

Cheers Vor, I just needed to change default to saved.