URGENT: xp doesnt want me to use my usb stick

hey, this is really urgent

i wanna transfer some files from one computer to another and when i put my usb stick into the usb port then turn the computer on it works, then when windows xp starts to load(befor login) it turns the light off it and doesnt think its there?

any ideas?

Have you tried putting it in after XP logs on instead?

Have you installed the USB drivers for the motherboard?