Sorry I don't have much knowledge of installing USB 2.0 on a 98 system.
For windows XP I would just go get Sp1, go to the device manager, right click the PCI card and press update drivers. There is also a device in WIN98, but I am not sure they work the same. No harm trying.
G. Skill 4GB(2x2GB) DDR800
eVGA 8800GTS 320MB
super pi: 1m=20s