If your Windows 98 PC is working then you have two simple choices
1) On the 98 box, copy the photos to CD if it has a CD writer
2) On the 98 box. copy the photos to a USB memory stick if it has a working USB port (not sure if 98 supported USB).
If you have a ROUTER in your house to split the broadband amongst a number of PCs then the next best choice is:
3) Connect your 98 PC AND your XP PC to the router and then set up sharing between them. This does require some technical knowledge but if you go down that route we can help you.
4) If you DONT have a router there are ways of connecting two PCs directly to each other using something called a "Cross over cable" but that again requires some setting up.
5) The final choice is to remove the hard disk from the 98 box (not difficult), buy an external hard disk caddy, put the hard disk in it (not difficult), then plug the caddy into a USB port on your XP box.
Then you can copy the files directly from the external disk to the XP box.
I think those are you main choices.