where did you get the card from? and what motherboard does the machine have?
I'm hoping it is one that should have USB2 support in its own USB ports - then we can point at some further problem with the OS install.
If it is a USB 2 card I didn't think the Motherboard's USB revision would influence it - I know it didn't with my old machine.
BTW
Does the case have a windows XP sticker with licence no. on it? (looking for the enraged customer approach to the shop)
Your OP says the card is USB 2 - get your techy friend to try it in his machine to see if it'll work there.