If you have an assembled PC, go to Motherboard manufacturer's website and download the latest BIOS and drivers for your version of Win7 (x86 or x64).
If yours is however a branded PC, you need to go to the manufacturer's website to do the same.
But generally, Win7 is very good with drivers. Normally you shouldn't have troubles unless the board is very old or something.
What motherboard are you using and which BIOS version?