I too have an XP laptop and a Motorola RAZR V3m (now called an IZAR V3m or some such). I used to tether the phone to the laptop via USB cable, using an old "Cingular" connection. It would work with a Bluetooth tether also. See if it still works:
Create a new network connection as though you were creating a dial-up phone line connection to an ISP.
The connection is to "WAP@CingularGPRS.com" (omit the quote symbols)
The "dial-up" number is *99***3# (include all symbols)
Please, post your results here for my interest. My laptop isn't available right now for me to check it out.