Ubuntu's repair tool is a nice feature, however having to do it over and over again could be a bore.
For example, on my HD, I installed Windows-7 on the first partition, installed Ubuntu on the second, installed windows on the third and Ubuntu on the first. After each of the Ubuntu partition installations, my grub menu got messed up and I had to run Ubuntu's repair tool. On the fifth partition, I installed Debian and again grub get messed up. Ubuntu repair tool came to my rescue.
I have a Ubuntu-12-Desktop CD which I use to recover my grub. A live-CD will also do the same job.
Boot your computer using your CD and when you get the screen below comes up, click "Try Ubuntu"
When Ubuntu loads, setup your internet connection; and using the following commands, boot-repair gets installed and starts:
sudo add-apt-repository -y ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair
The boot-repair screen pops up, click "Recommended Repair..."
Accept any other defaults. At the end, you will be asked to reboot.
Thats all folks.
I need to investigate how to get this done offline, without an internet connection.