HeHe - CookieRevised always here to straighten things out.
Never have two antivirus programs
I recomend it - Different antivirus/adware/spyware/etc. pragrams pick up different things and are aimed at different types of threats ,for example, Adaware picks up more adware than norton which picks up more torjans and other viruses. Some do conflict but as long as they don't - more is better to ensure you remove ALL threats.