Have a question about Win7 and dual boot

[Mortuus]

I have XP installed on one partition as usual (c:/) and i would like to install Win7 on my other partition to play the BF3 alpha but im wondering is it possible to install win7 on a existing partition with enough freespace or will it write over all my files its almost 100gb so i dont wanna loose stuff really i have googled this but not found a definite answer.

 

[Lord Nassirbannipal]

If there are files on that volume, then yes, everything will be lost when you install Windows 7. If you need to dual boot, then you'll need to move those files shrink the volume to create another one for the 7 install(you can do this is disk management).

While you're at it, is there some reason you need to have XP? Other than the pain of having to reinstall all of your apps and configure your preferred settings, etc, why not just install 7 as the only OS and be done with it?