VIPRE Advanced Security is high-performance security software that doesn’t slow your computer down like older, traditional antivirus products that have been around for years. VIPRE combines antivirus, antispyware, anti-rootkit and other security technologies into a seamless, tightly-integrated security solution. VIPRE delivers comprehensive protection against today’s highly complex spyware, viruses, and blended malware threats.
I have been using Free and Paid AVG antivirus for most of the last decade and found it to be great but the last few releases from v7 onwards have become more and more obtrusive, like Norton and Mcafee and this tends to slow your PC and interupt you when you need it least.
I installed the trial of Vipre in October 09 on my main development machine and was so happy with it that I bought a license for all our machines in the house and office. It just works! And it doesn't get in your way. Its also very inexpensive.