What motherboard make/model? I can provide you with a link to the driver (probably) if you tell me what motherboard you're using.
If you are using a pre-built computer such as Dell, HP, Compaq, etc etc, then you'll need to provide the model number and manufacturer of the computer.
EDIT: Remember this for next time. I always burn a CD with all of the drivers (32bit AND 64bit for various Operating Systems) before installing new OS. This will save you time and frustration.
You're going to need to burn a CD on another computer, use a USB thumb drive, or take the hard disk out and put it in another computer. There are a few other methods, such as using serial or ltp ports to connect the two computers, but it's slow and easier just to burn a CD.