How to Triple Boot

First to do the triple boot, you will need to make partitions, in this case 3, one per os. You can use gparted to do that, you can download at here. After you have done that, install each os in each partitions. At the end, you will only be able to use one os, the last you installed. Now to make the triple boot, you will need the software easybcd, and you can download it from here.

Install the easybcd software. You've installed it, open the exe, note that in order for it to work in xp you will need net framework 2.0.

1. Go to the manage bootloader tab, and click on "write mbr"
2. After step one, go to the add/remove entries tab
3. Now in that tab, choose the drive letter, and after that, select the os, and click on add entries. Do the same for the other os, and you're done