Most of the time, antivirus is not required.
You might want to concentrate more on HIPS, like PC tools
Threatfire.
Intrusion prevention systems (IPS) operate on the
principle of monitoring the
user's activity in his and her system taking required
action based on behavior. It then prompts you for action or does
it's pre-default programming. Pop ups and notifications are very
common of such softwares or suites containing such
software.
It is not a replacement for an anti virus/
spyware solution. It works along side these
software to provide a more comprehensive protection for the user.
That's said, even with such options, your PC may still be
infected without your knowledge which is a
fact.
Anti viruses remove threats from a signature base. This removes
it based on activity. If your pc has already been infected by the
malware, what IPS does is to quarantine the active parts of the
malware. It does not clean off.
Almost every major security firm, Free or paid, has their own
forms of detection and monitoring. Now most Paid Security
Suites/Anti viruses NIS, Mcafee , free alternatives like AVG,
MSE, feature many kinds of passive network monitoring software
or intrusion preventing systems, funct .
So what are you really saying actually?