After installation I could not boot into Mageia. It was invisible as a boot option.
After much frustration i did stumble across a very simple solution. It should work for anyone having this issue.
Assuming you know where you put the distro. Mine is on sda1. You must open terminal or konsol. Commands for konsol might be su instead of sudo
First command I entered in the terminal is: sudo mount /dev/sda1 /mnt .... Then entered my password when asked.
Second command I entered is : sudo grub-install --root-directory=/mnt/ /dev/sda
Third command I entered is: sudo update-grub
I mash the enter key after each entry. After the final entery I reboot and boot to whichever distro on any drive. They all show up.
This solution should work from any location on any drive including a live session. On my computer with three drives and 5 distros I used it from a different working distro on a different drive.
I found this process at the following site: http://community.linuxmint.com/tutorial/view/245