I have noticed that many people today think that

"more is always better"

When it comes to PC Security Programs--

Exactly the opposite is true

Firewalls/Antivirus/ and Spyware scanners-- often have active components that run unseen in the background on your PC.

This causes problems if you have more than one of each type installed on your computer.
These programs depend on being "in charge" when it comes to protecting you-- the methods vary slighly from Program to Program.

If two antivrus apps are running at the same time (for example) and you get a virus in an email... and you try to open it-- both apps will react at the same microseceond-- quite probably interfering with each other-- and perhaps allowing the virus to get through.

The same is true for Firewalls

You should have ONE and ONLY ONE
of each on your machine.

Anti-Spyware apps may have some overlap coverage with your AV... this is alllowable-- I've never had a problem because of it.

If you want to do extra Anti-virus scans "to be absolutely sure" you can still do so-- go online and use one of the free antivirus scanners that work in your Browser. If you do an online scan-- be sure to use a different site than your installed AV version-- this is to cross-check with a different database.

Trend Micro HouseCall - Free Online Virus and Spyware Scan - Trend Micro USA

BitDefender Online Scanner - Free Online Virus Scan

Free Virus Scan - Kaspersky Lab

Free online antivirus. Download ActiveScan and clean your PC. Panda Security

F-Secure Support pages: Home users#

Eset - ESET Online Scanner