I have managed to install Ubuntu 12.04 LTS and it's great so far! All I need to do now is to resize some partitions on my hard drive (namely, my boot drive). In order to do that, I need to boot into the installer, go to "Try Ubuntu", then use Gparted to resize my boot partition. However, when I tried to do this using the same live USB stick that I used to install Ubuntu 12.04 in the first place, I am not prompted to the installer screen; my machine simply loads GRUB. Are there any configurations that I need to do?