I installed VISTA on my other computer, and it gives me the expected boot loader screen when i boot asking if I want Vista or XP. But I try to install VISTA (I have two licences) on my other PC, and without the vista PC, it boots into XP, with the vista CD it boots into vista (provided of course I don't hit a key, when it says to hit key to boot from CD)

REALLY — I DONT CARE WHY VISTA DIDNT INSTALL THE BOOT LOADER — I JUST WANT TO KNOW HOW TO INSTALL THE BOOT LOADER, SO I GET A SCREEN ASKING ME WETHER TO BOOT XP OR VISTA WHEN I START MY PC.

The Answer by www.komando.com :

So, you want the Bootloader Menu to give you choice of which OS you want to run?

The the following steps are the same for both XP and Vista. Go to System Properties (right click My Computer, choose Properties), click Advanced tab, then click Settings under Startup and Recovery, make sure there is a check mark on the first box that said "Time to display the OS" and set the time (in seconds) for how long you want it to be waited for you before it goes to the default OS (by the box right on the top of this check box), then OK, OK to exit.