Hääääää?
You have a live-cd, that installed a bootmanager?
normally, the bootmanager is on the cd -or it puts one on a floppy ... by the way ...
if you install a new linux-distro, it will ask you, where the bootmanager (os-loader) should be placed. you should choose the first harddisk. There, it will be placed on the "master bot record".
You ca flush it with booting with a DOS-floppy and typing "fdisk /mbr" - but then, all entries will be gone. So it´s better to let the new distro create a new entry ...
Greetz
Pete