First, find out what phone you have and write it down. (is it Nokia E65, Nokia 7370, Nokia 6700 classic? etc.)
It will be on the box, maybe on the phone front, or take the battery cover off, it should be written in there.
Click on link below and scroll down to table.
http://www.nokia.com.au/get-support-and-software/download-software/nokia-pc-suites/compatibility-and-download#download
Type your model number in where it says: [Search for your device model in the table below]
Go accross the line for your phone and click on the blue: [7.1]
Click on [Run] Button. Follow its instructions, tell it yes and keep clicking right arrow >>> when it asks you, and let it restart your computer.
I am also running XP and I have tried it on my computer. It should work fine.
Hope this helps.