15 pts.
 More than one AV software
I have seen many postings on different sites that recommend using more than one anti-virus software package. Yet every time I contact a vendor with a problem, the first thing they want me to do is UNINSTALL (not disable) all other AV software. Is there a significant problem with having more than one AV installed on a machine?



Software/Hardware used:
Vista, KAV 2009, Spyware Detector
ASKED: August 24, 2009  2:18 PM
UPDATED: February 22, 2010  5:48 AM

Answer Wiki:
Spyware Detective? There was a rogue anti-virus software package named Spyware Detective. Rogue anti-virus software packages are actually trojan horse programs; you're encouraged to install it for some reason when there is actually a malicious payload. I would guess that installing Spyware Detective is causing your problems. Meanwhile ... anti-virus vendors will not claim compatibility with other anti-virus products. Of course they will ask you to uninstall other anti-virus products. There is no specific, significant problem with more than one product. There is no specific, significant benefit either. Before installing that next package you download, upload it to VirusTotal and see what a multitude of anti-virus vendors think about it. For years I have been using Avast. That alongwith regular windows updates has so far kept me safe. And Avast has a smaller footprint, much smaller compared to Symantec or McAfee
Last Wiki Answer Submitted:  August 30, 2009  1:49 pm  by  Rklanke   1,235 pts.
All Answer Wiki Contributors:  Rklanke   1,235 pts.
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Two antivirus programs could conflict with each other; and since AV systems usually use a huge amount of resources of the machine, having more than one could also have a noticeable impact on performance.

I usually use one anti-virus, a firewall, and one or two anti-spyware programs on the same machine, without any problems.

 63,535 pts.

 

I agree with Carlosdl. Two AV applications could “beat-up” on each other and cause system performance issues and crashes. There are a couple of times when it might be useful to have more than one AV available for use:

1. When a machine appears to be infected with an unknown virus. Scan it with multiple AV applications to see if the others can detect what one cannot.

2. When a system is infected and you are trying to clean it out. This is a corollary to #1. Except, if a machine is infected by a remote control or access trojan and/or rootkit, it should always be reformatted as you have no real way of knowing the integrity of system files (not going into something like Tripwire here for file monitoring).

Bottom line: run only one AV at a time.

 0 pts.

 

That makes sense, but the support group with Kaspersky wanted me to UNSTALL all other AV AND Spyware. Fortunately, I found the problem (“Protection not Running” messaqge from KAV) and it was NOT related to SpyHunter being installed. You and Troy Tate raise a question: What is the difference between a program like SpyHunter and KAV and Spyware Detective? Spyware Detective (Max Secure Software) loads processes on startup and even if you “EXIT” the program they keep running. I don’t remember, but I do not think Task Manager is able to stop them. SpyHunter does not leave processes running on exit. Spyware Detective also has an AV engine and its tech support said I did not need anything else.

I apparently had some really bad bug that no AV could detect, not even the Kaspersky on-line scanner. Sfc/ scannow found corrupt files, but could not repair them. MicroSoft support diagnoed a virus. (or some bad bug). My solution to the problem was to bite the bullet and reinstall the operating system. All worked fine….for a month or so. Then I began to have startup problems…Vista got hung on startup. I also have Registry Fix 7.1 on my machine and did a complete registry backup when things were running perfectly. So I restored it when problems began to appear and for now all works well… I am using KAV2009 (soon to update to 2010) and SpyHunter. I only run SpyHunter once per week as a check on KAV. It ALWAYS finds dozens of cookies, which I routinely delete.

 15 pts.

 

 

My philosophy, as it has been since ~1993, is pick an AV vendor and stick with it.

That said, there’s nothing wrong with covering all the attack vectors with products from different vendors; at home, I use avast! for AV, Spybot S&D for anti-spyware (especially for the resident TeaTimer), and BHO Demon to watch for the installation of IE browser helper objects that I may not have been aware of. I’ll also fire up Adaware to do deep scans, which seems to catch more; and on my Vista machine, Windows Defender also plays a role.

As with a medieval castle, a layered defense is the way to go IMHO.

Or you can install Linux. :)

 680 pts.

 

I can just barely stand having one anti-malware product on my system much less two!

 10,840 pts.

 

If you consider outsourcing antimalware, check out this technical tip first:
The pros and cons of outsourcing antivirus services


 

could I share this too? last time a friend of mine decided to install 3 antivirus program on his laptop. After installing the 3rd, his pc could not even startup and we have to go thru the whole process of going into safe mode and removing the latest installed antivirus.

I asked him why did he install so many antivirus and he told me it was for extra protection :P

 15,485 pts.