Ok here is what i want, im currently using Windows XP Pro 32bit (genuine, meaning i bought it) and is install on one of my 2 HDD. The HDD is installed in, has being divided into 2 partition, one for the HDD (40GB) and the rest for programs. My second HDD is 640GB and all it has in it is games, music, videos, etc and i have 280GB of free space, but its just one big HDD not partition. What i want to do is resize my 2nd HDD and use 100GB to install Vista Ultimate 64bit. But here is the thing, as you can tell i want to Dual Boot, but i want to make sure XP stays my main OS, cuz my Vista is going to be a pirated one, and all i want is to try it out and be able to buy the a new one, which is y i only want to use 100GB. what i want to kno is if i follow whatever steps are given here to activate Vista would it damage any of my XP files, or this activation needs only to be on an one OS running system since i have to change BIOS years during the process. N also whats the easier way to do this and best way that atleast 2 or 3 months from now once i get Vista (hopefully by Xmas as a gift) i can unistall this one and reinstall it with the Valid one. I hope i can be understood and help