how to triple boot xp, backtrack and 7? I already installed ubuntu inside windows so there's no problem, but then my thirstiness is telling me that I should install backtrack linux, so that I could have 4 operating system running on my computer.
Backtrack is not really designed to be a main operating system, it just has a lot of tools and works really well from a live cd... In fact, I may of missed it, but I do not even think it has an installer.
I would advise you just dual boot XP and 7 like normal (install XP first, then Windows 7 - as the newer OS, it knows XP and can install safely along side).
Personally, when it comes to Backtrack, I run it inside a virtual machine and pass through a USB Wireless adapter so it can do it wireless "magic".
At the end of the day, unless you have real reason to use XP, you may be able to get away with just running it 100% virtually inside Windows 7 with XP Mode or a XP virtual machine with your favourite virtualisation software.
If you already have everything installed you can use EasyBCD to setup your boot-order