I have Adware and Spyware on my computer which i cant get rid of, help?

I've recently discovered lots of adware and spyware on my computer. The adware is terrible as I get pop-ups with naked women and randomly coming up on the screen and this is not good with the younger kids go to use the computer. I'm also very wary of accessing my bank accounts and using my debit card on the internet incase the spyware captures my details. My anti virus software can't detect the adware and spyware at all. I really need help to get rid of this horrible virus!