There are a number of good commercial programs that will handle protection of your system as well as detection and eradication. The following programs are comprehensive and have been updated very quickly in response to new threats. You will be well served by any of these programs.
Anti-Toxin: Very easy to use. Effective.
Virex: Easy to use. Effective.
Symantec Anti-Virus (SAM): Very comprehensive. More difficult to use.