You should check Yoda's Help Desk (http://yodashelpdesk.lucasarts.com/
) at Lucasarts.com. They usually have the answers and if they don't you can contact them about it.
I did some searching, and the support doesn't have anything about Windows XP. 98 SE is the highest it goes, but I saw at least two entries which might be related to your problem. Your problem might not even be XP specific.
So when you get to Yoda's Help Desk, under 'All Games' pick Star Wars Droidworks. Next, select Windows 98 SE. After that select 'All FAQs'. You'll see a list of questions which provide some pretty details and easy to follow answers and directions.
If none of that helps, click on 'Email Tech Support' and they will try to help you out. I don't have the game so I can't really help you myself, but they can.