We recommend two antivirus programs which have been proven to detect and stop almost all viruses and exploits:
The Norton Internet Security package includes antivirus scanner, two-way firewall, antiphishing and antispam tools. It can also protect your mail client and instant messenger from viruses and your wireless network from unauthorized access.
Kaspersky Internet Security protects your files and email; it can filter your applications, traffic and content. The package includes spam and phishing protection tools, parental control and banner ad blocker.