Reinstall Vista to get rid of viruses

Hello,

My laptop has some serious viruses. I was told that I can reinstall Vista and start fresh which will wipe out all the virusses. Now, I am not sure if I still have the Vista CD, actually cannot recall getting one when I purchased the laptop. Anywhere I can get another CD without paying an arm and leg for it? Or, is there a different way to erase the virusses on my laptop without spending ridiculous amounts of money?

THANKS ANYONE :)