what sort of computer is it, if it is branded (i.e. dell etc) goto the makers website and the drivers should be in the support section.
if it is a home/custom build system of some sort can be a bit harder. concentraite on network first once you have that least you can go online to download the rest.
Maybe a case of taking the card out to see what sort of card it is.
Ethernet, video and audio not supprised at, USB is a little strange as that normally installs fine, you may need motherboard or chipset drivers
When you do locate all the drivers put them on CD so you have your own system restore CD ready for next time