Is it Safe To Use Two anti-virus engines?

Hi Guys

I would like to discuss this subject in more details with respect to the worth or perils of using two on-access anti-virus engines. Some people, like me, would say yes, but… However, most people would adamantly say no way.
The bottom line for me is to have people opinions; if you agree please state why. If you do not agree please also state the reasons for your disagreement. More importantly, be respectful of someone opinions even when you disagree, since knowledge does not inhabit one brain alone.

Let us brainstorm together and share respectfully our ideas.


Well , having more at the same time could increase your detection. However, they could also lower your defences and they use a lot of system recourses. Myu personal experiences are that it isn’t necessary to use more than 1, however it is adviced to just use the others as on-demand scanners.


Hi Experience

Thanks for your reply and you have stated the truth. However not all multi-engine scanners are a drain on system resources; for example F-secure anti-virus which is a multi-engine scanner did not slow my computer down at all. I downloaded their trial and I had no issue with it.

Currently my NOD32 will expire soon, very soon and I’m using it with Dr. Web side by side both on access without conflict nor resource drainage on my system.

You do not need 2 av’s. Plain and simply.

Thanks for your reply and you have stated the truth. However not all multi-engine scanners are a drain on system resources; for example F-secure anti-virus which is a multi-engine scanner did not slow my computer down at all. I downloaded their trial and I had no issue with it.
Could be, I've never tried it. :)
Currently my NOD32 will expire soon, very soon and I'm using it with Dr. Web side by side both on access without conflict nor resource drainage on my system.

You could visite my combination topic which includes several shareware long trials

Aaaaaaaaah, I was waiting for that reply Vettetech ;D


Just like Vet mentioned, there is no need for 2 anti-virus.

Now, is it possible without turning the system unstable? Yes, it is. But it all comes down to what anti-virus you choose.

For example, it would be perfecty possible to have both NOD32 and Avira. They are both light on resources.
If you truly wish 2 anti-virus engines, you can then use NOD32 (paid) as the main anti-virus and use Avira AntiVir Personal (free) as an on-demand one and turn some of it’s services off on the windows services manager.

Hi Vette

I beg to differ from your point of view. Actually using 2 anti-virus engines is my own response to the in-the-cloud technology that cost a fortune (trend Micro is a big proponent of such a technology). ;D. The threat landscape has changed. I’ll state more reasons throughout this thread of the worth of using two anti-virus engines.

Peace man

Fact is that standart antivirus scanners only rely on signatures. That’s why I use Comodo Firewall Pro. It Prevents stuff, so I don’t need any on-acces antivirus. Vettetech uses CFP + an antivirus. He doesn’t believe in using more as it is together with Comodo only as a back-up. I only use them as on-demand scanners.


Hi DarkButterfly

I already tried NOD32 and Avira together both on-access without turning anything off with great success, no problem. It is OK to use two anti-virus engines. Please do not be afraid. Please do not be afraid :-[.

true, be not afraid. We only share differend visions as you stated in your first post :). You could use some together but be carefull, some will clash.


Hi eXPerience

You are right, some will. By virtue of experience ;D I know that NOD32 and Avast do not co-exist well I tried them already on my virtual XP Pro SP2. To me I think Avast was at fault since NOD32 is quite tolerant of other antivirus engines. The worst though is TrendMicro.

Also eXPerience tell us more about the ones that will clash.


I can tell you that if you install AVG 8 while having one other antivirus installed, the system will hang. The same thing does not happen if you first install AVG and the other antivirus.

If you install both NOD32 and Avira AntiVir Premium, then (it was how I made the test) you will have to deactive some services of AntiVir, otherwise system will take too much time to boot (taking in account what you got loading on system startup).

Hi DarkButterfly

Not quite so and I already tried them. As a matter of fact I tried AVG 8 Pro with NOD32, Avast, Avira free and Outpost antivirus without any headache. I installed AVG 8 first and then the other engine and after about two hours I powered off the the virtual XP and installed let’s say Avira first and after that AVG 8 with the same results, no problems whatsoever. :slight_smile:


Before this thread goes on and on. There is no proven fact that 2 av’s are better then one. AV Comparatives and other test sites like it do these tests on system using 1 av at a time. Most of today’s av’s catch about 95% of whats out there. Thats ■■■■ good. I have always used 1 av and a firewall and always been fine. Now I am running Sandboxie also. I have never been infected but just the other day a ran into something and Comodo alerted me. NOD32 removed it and when I emptied my Sandbox it was gone completely. I did some chatting awhile back with an NOD32 designer and her even said 2 av’s can cause conflict and actually make you more prone to infections. Having a good av and 1 as on demand is fine. Dr. Web Curit is good. Thanks eXperience for speaking up for me. I was at the track running my Evo. Sure you can run 2 av’s with no problems but why? Its a waste of time and resources. If anybody should be infected around here it should be me. I surf and download everything in site and my system is still clean. Some people dont even use an av. Some just use Comodo. Others just use Returnil. Some use nothing. Others use Sandboxie. Read my thread here. If somebody can prove to me that using 2 av’s is better then one with extensive testing and proof be my guest. You can have 3 av’s running,2 firewalls, 2 behavior blockers all under a Sandbox and still get infected. Nothing is 100% effective. BTW Jaki…why did you start this thread if you seem to know the answers.

Hi Vette

You are so wrong. The facts are there are more and more companies that are adopting multi-engines technology, some are better than the other. Take for example Gdata, F-secure, and TrustPort. These companies have a market based on real customer demands. Without such a demand any company would not have any revenue and consequently they all will be out of business.

Also any new idea or concept will obviously face resistance against any accepted convention, but that is how science and technology advances by challenging the statu quo. The concept of one anti-virus engine has had its time. Bottom line if companies like Gdata, F-secure etc are producing more version of their products mean that they are spending their own money and they expect a substantial retrun on their own investment. If that is true I can logically deduce that their finished product are products that a least a segmeent of the information security market want. What company that will willingly invest in a losing investment? I like such a product as well as many others and more of us are growing in numbers.

That all the proof I need. and more are coming up.

I think not much of the users choose G-Data or Trustport, maybe companies or some really paranoid or inXPerienced people ;D
Multi-engine producs are effective, but are heavy and produce more FP’s. Have you ever heard about Sybari ? It’s a company bought(owned) by Microsoft. Some time ago Mr. Eugene Kaspersky said that once Sybari comes to the market with their multi-engine antivirus solution Antigen (and I mean something like Virus-Total on a PC ;D) other antivirus makers will get a big ■■■■. And what happened ? Nothing ! There is really no practical use of them for now ! But of course - by 2010 we will have 5 million viruse around, maybe even more so those multi-engine monsters will be more and more on-demand, but now - they are just an overkill of a regular home user PC. IMHO :slight_smile:

My Dear jaki…G-Data and F-secure are stand alone applications. Both of them combine av engines so its like 2 av’s in one. But it is not the same as running 2 separate av’s It is 1 av using 2 engines but still only using the same services. Running NOD32 and Avast at the same time is making 2 av’s compete for each other. This is not what G-Dat and F-secure are doing. It was a program designed to do that. You are not a program designer and running 2 individual av’s each with its own services is no where near the same as G-Data and F-secure. You started off you thread asking us if using 2 av’s side by side is a good idea. which clearly it isnt. Now your talking about G-Data and F-Secure which is still 1 av. G-data and F-secure do this with out extra needed services. Good day and God speed.

G-data = 1 av with 2 engines. No overlapping of extra services
NOD32 and Avast = 2 av’s, 2 engines. Tons of overlapping services.

When I just looked at AV Comparatives I see no proof that 2 engines is better then one. The highest scoring av is Trustport with a 99.8% effectiveness. Then Avira and Sophos with a score of 99.6%. G-data gets a 99.5% effectiveness and NOD32 gets a 97.7% effectiveness score. Avast which is free gets a 97.6. All of these scores are within fractions of each other. Avira uses 1 engine and scores higher then G-data. No home user users Trustport or G-data that I know of. Hardly anybody uses F-secure. You still are not showing me Proof Jaki. Run some tests. Show me that using 2 separate av’s is better then one. G-data and F-secure do not fall into that category.

My Dearest Vette

You are once again wrong, Gdata as well as F-secure etc do not combine their anti-virus engines. These engines are very distinct from each other with respect to Gdata database architecture for example. You could have the choice to use both on access or one of the two while the other could be on demand. There is no doubt that they are not combined.


And you made this thread why…?