I did a fresh install of Ubuntu 11.04 on a HP 550 Notebook. But grub2 isn't really fit in the best screen resolution that this Notebook can support (1280x800).
How can I do this without using a third party application ?
To do this safely requires two steps.
Step 1: find the preferred mode
Reboot and press and hold Shift to display your grub. Press
This will display various stuff how grub recognizes your display. At the bottom is "preferred mode" - in your case it should say 1280x800. Note down the value.
Note: sometimes, some buggy video cards incorrectly give Grub the wrong preferred resolution - if the preferred mode is much higher than you were expecting, then select the nearest mode in the list displayed that you were expecting.
Press Esc to return to grub and press Enter to boot.
Step 2: Setting the resolution in grub
Reach for your terminal and type
find the line
save, then type
Note: the preferred mode has to be among those listed by vbeinfo. For example, if your preferred mode is 1920x1080 (a common 16x9 aspect ratio setting), your preferred mode is NOT supported by vbeinfo and may not work correctly. In fact, there do not seem to be any 16x9 modes supported by vbeinfo, as of Ubuntu 13.04. In that case you could try falling back to something common like 640x480, which, it seems most monitors support and vbeinfo supports. Also, not all the modes supported by vbeinfo are necessarily supported by your monitor and you may have to experiment.
I'm using Ubuntu 16.04 and things are a little different in the packaged version of Grub for me.
I am running 14.04LTS on an ASUS M51AC with an Nvidia 625GT OEM. I found that in addition to the accepted answer, I needed to also add the line:
Easy to use Grub2 settings customizer. Go to "Preferences" -> "Appearance"