ethernet conection dont light up or work?

i put a new mother board board in my ethernet dont light up or work it was a vista machine but when we changed the motherboard vista said illegal copy of vista so i put windows xp on machine every thing works except the ethernet port. network adapter says speedstream ethernet usb adapter #2 my modem will work by usb or ethernet am useing on usb but dont know if it is getting all the speed of my connection. all i have is a 3 mb but only get 1.5 speed from modem.so upgrade to 3 mb didnt speed it up .6

 

When you replaced your motherboard, was it an EXACT replacement, or another type?