first, take the card back out and see if the computer works ok. if it does, try another pci slot ont he mobo and see what happens. if this doesnt work, see if u can dl some drivers from the manufac. website of the usb pci card. and if u do all this and same prob, and it doesnt happen with the card unplugged from the mobo, i say exchange it for another card from wherever u bought it from.