If you have a low screen resolution at starting up Ubuntu 10.04 after installing graphics drivers,you can try following method to set the boot screen resolution to what you want.
First,edit /etc/default/grub file in with this command Applications->Accessories->Terminal:
sudo gedit /etc/default/grub
add this line into the end,and save the file:
here change 1024x768x32 to what you want.
Finally,update grub to apply the change: