Assuming your monitor's drivers are installed, Win XP should recognize the refresh rates each resolution supports. I've had no trouble making full usage of the absurd refresh rates aperture grill CRT used to offer.
However, if the drivers are installed and you're still having trouble upping the refresh rate, just download a separate software like ReForce to force the desirable refresh rate. I used it back in the day to bypass Win XP's infamous 60hz limit, and as long as you don't set something which your monitor doesn't support, you're safe.