well as it shown in the title ..i'm wondering if i can install 3 oprating systems on my computer ..i have ubuntu and windows vista dual boot already (yes windows vista still working with it because of sonyvaio didn't make this computer to support other operating systems ,whatever that's not our topic) so i don't want to replace ubuntu 13.04 with backtrack and i'm wondering if i can keep up on them all .. I installed backtrack on vmware workstation but its very slow and had so many problems and i don't want to install it on vmware or virtual box but a dual boot or triple boot lol ..help guys .. tahnks alot :)
Yes, you can install as many OS as you wish. There are posts with up to 150 OS installed on one computer.
Please note that that is an old post using an outdated version of grub. Everything should work out of the box when you install and / or update grub.
If you have a problem, ask.