I am a professional photographer who exclusively uses Corel Paint Shop Pro Photo X2 (I highly recommend)and although Corel has its own monitor calibrator built it, my experience with it has been less than satisfying. I would rather independently have the option of calibrating the monitor separately from my photo editing software anyway.
I maintain three computers, which all run Windows XP, one has a flat screen monitor and the other two are the older TV-style monitors.