In my laptop I currently have Windows 7 and Ubuntu 12.04 in dual-boot.
I tried the newest version of WattOS (based in Ubuntu) today from a live-USB, and decided to install it to my hard drive, to use whenever I am completely dependent on battery energy.
However I don't want to create any conflicts and boot problems, specially because my DVD drive is not working and thus I am unable to use Windows 7 DVD to repair MBR.
What is the safest way to install a second Linux distribution (in this case Watt OS) and update Grub Menu, without major trouble?