Here's how you can get Clean-Ubiquity, a utility that will make installing Ubuntu safer.
1. Go to the Clean-Ubiquity site.
2. Click the green download button on the right side.
Here's a description of Clean-Ubiquity:
"Clean-Ubiquity is a small (<100ko) addon for Ubiquity (the Ubuntu installer).
It automatically performs a backup of the MBR of:
1) the partition tables of all disks
2) the MBRs of all disks
before Ubuntu's installation. No visible change for the user.
If one MBR is altered by Ubiquity, Clean-Ubiquity links its backup with the UUID of the new OS.
This special backup can be automatically restored via OS-Uninstaller and Boot-Repair (see https://launchpad.net/os-uninstaller and https://launchpad.net/boot-repair ).
This can be extremely useful if the computer is MBR-locked. MBR-lock is a system that can be found on some OEM computers with pre-installed Windows. It is (was?) put in place by some manufacturers in order to fight against Windows piracy, by preventing or making difficult the use of a Windows with a different version from the one that was originally on the computer. MBR-lock is now forbidden in some countries (e.g. France), so it should not be on recent computers. Basically, this system uses data written on the motherboard and/or the MBR. If the MBR has been altered (e.g. by GRUB), this system will detect it and prevent Windows (or the entire computer) to boot.
Clean-Ubiquity needs 2 preseeds integrated during the ISO building."