Another easy and viable option is XOSL. It is very user friendly and does everything you would ever need. Plus it's free!
Basically what it does is when it boots, it will give you the option of which OS to boot to. Whichever one you choose, it effectively masks the host hard drive to show as letter C. That means that when you are in MC, the SATA will show up as your C: drive and when you are in XP Pro, the IDE will show up as your C: drive. This program tricks the computer into thinking that the drive (which may actually be D: or E: on one OS) to show up as C: for the current OS that you are running. It works fine and never has any problems so far. I use it on 75 laptops at my place of work.
You can find info and downloads at
XOSL: Extended Operating System Loader