Found a much newer chipset driver at Nvidia site.
That's what I meant by "update".

If that still doesn't work, replace the following files from a known good system or from the XP CD. Preferably, use a slipstreamed XP SP3 CD.

put .inf files in C:\Windows\inf
usb.inf
usbstor.inf

put .sys files in C:\Windows\system32\drivers
usbd.sys
usbehci.sys
usbhub.sys
usbintel.sys (i'd skip this one since you have an nvidia chipset)
usbport.sys
usbuhci.sys

If you don't know how to get system files off the XP CD:
http://www.winxptutor.com/expand.htm