Configure the Grub Menu in Ubuntu 10.04

Grub will be installed when Ubuntu installation detects another OS on the disk, and the Ubuntu system is always has the priority in the boot list by default.
Here is how to configure the Grub Menu to change the OS sequence.

Go to Applications->Accessories->Terminal, enter
cp /boot/grub/grub.cfg /boot/grub/grub.cfg.original
  #make a backup of original configuration file

sudo gedit /boot/grub/grub.cfg
  #open the grub.cfg in GEdit with root privileges

Inside file, search the blocks start with "menuentry", these are the boot menu entries. Comment those unwanted ones to disable them, and move up/down the block to change the sequence.

After editing, save the file and reboot, and the new Grub Menu will take affect.