|The 1st thing you need to do is create a dedicated partition for Win7. Once you've done that, just boot into XP, then pop the Win7 disk in the drive. When the menu pops up, direct it to install onto the new parition.|
Make sure you enough RAM or you'll be disappointed with the performance. Microsoft claims 1GB to be the minimum, but you should actually have at least 2GB, more would be better. Also, make sure you have (or can get) all the required Win7 compatible drivers.
IMHO, Mint 11 > Win7.