Problems in booting:
Unable to boot or want to change options of grub2? Here is the answer!
For earlier Versions:
StartUp-Manager was a free open-source GUI tool to manage settings for Grub, Grub Legacy, Grub 2, Usplash and Splashy. It provided a menu-driven interface which allows the user to set boot menu options such as the default operating system, menu timeouts and displays, password protection and much more.
StartUp-Manager is now obsolete and its development stopped since 2011 as it was incompatible with Ubuntu 11.10 and newer versions of Ubuntu.
Now after Ubuntu 11.10 to 12.04:
The substitute is Grub Customizer (a graphical grub2 settings manager)
Add following PPA to the repositories (through software center or update manager):
Now open Terminal (Ctrl+Alt+T) and type:
Sudo apt-get install grub-customizer
Enter password and type Y on next question and it is done.
BTW the official site of developer is here. It provides tar.gz file also if we want to do it hard way.