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Why are my two anti-virus tools giving different results?


XP Pro, Spyware Doctor, and Microsoft Security Essentials. Problem happens
every time I have two anti-virus software. Spyware Doctor and Microsoft
Security Essentials. I shut down Spyware Doctor completely and run only MSE for
two weeks and not one single virus. I then close down MSE and start up Spyware
Doctor and run it for two weeks and I get plenty of low risk stuff needing
deleting and some occasional virus. What does this mean? That SD’s findings are
false positives or that MSE is not doing the job right? I understand that you,
Leo, use both and recommend them.

In this excerpt from
Answercast #18
, I look at a case where anti-virus and anti-spyware tools are
showing different results and discuss why that may be happening.


Anti-malware programs

So I do want to be clear about one thing: I do not necessarily recommend Spyware Doctor.

I don’t dis-recommend it. I’ve never used it; I’ve never played with it.

I would caution you about interpreting advertisements on my site as recommended by me (even if the ads include the word “recommended” which means being recommended by the advertiser, not me.)

In fact, at the bottom of every page of Ask Leo!, you’ll see a statement that links to a more lengthy article which basically boils down to the fact that ads on my site don’t imply endorsement by me.

So, I can’t speak to Spyware Doctor’s specifically. Like I said, it’s certainly not something that I’ve personally have ever recommended or dis-recommended.

Anti-virus and anti-spyware

Now, a couple of things come up here.

One is that it’s well known that not every anti-malware tool catches every piece of malware.

  • Microsoft Security Essentials, which is both an anti-virus and an anti-spyware product;

You’re comparing to

  • Spyware Doctor, which from its name would imply it’s only a spyware program and not a virus-catching tool, an anti-virus tool.

It doesn’t surprise me that some, as you put it, low-risk stuff would show up in one and not the other.

Tracking cookies

For example, the most common case that I see all the time, that I hear from people about all the time, are so-called “tracking cookies.” A lot of anti-spyware tools will warn you to varying levels of urgency about tracking cookies.

Now, tracking cookies, in my opinion, just aren’t a big deal. They really aren’t. I mean, you can make some decisions about that on your own; but they’re not the kind of thing that warrant some of the red alerts that you get from some anti-spyware tools.

MSE, for example, doesn’t report on tracking cookies at all (to the best of my knowledge), which is exactly how I want it to be.

So it doesn’t surprise me that you might find some low impact stuff that a tool like MSE might not report on.

So, that’s about as clear as I can get on these two specific tools. I will throw you at the article, “What are tracking cookies and should they concern me?” in case what you are seeing are in fact tracking cookies.

One tool should be enough

Beyond that, I’d have to know specifically what kinds of things you are seeing.

  • I would probably live with MSE by itself and not worry about having an additional spyware tool.

The only spyware tool that I tend to recommend in addition to Microsoft Security Essentials is the free tool from That I typically only recommend when you actually are experiencing a problem. It does a good job of removing a few threats that a number of other tools don’t necessarily find or remove completely.

So that’s where I think you’re at. I don’t really see a huge problem here other than making sure you are keeping MSE up to date as possible.

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7 comments on “Why are my two anti-virus tools giving different results?”

  1. Thank you so much for that great explanation on why I am getting some items show up in one AV program, but not the other. I can feel confident now that MSE is doing a good enough job on it’s own, and so I will now leave Spyware Doctor disabled (as it does use up some memory sometimes) and just leave MSE active because it hardly uses any memory at all. So little in fact, I sometimes wonder that it is even working. If I get into trouble with a virus that has got passed MSE, I can then hopefully fire up Spyware Doctor to eliminate it… or even Malwarebytes. Thanks for your help…. mike

  2. Call me paranoid.
    I have always used at least two programs, precisely because “not one tool can catch them all”. MSE does a great job, but I like to have the comfort of knowing something else is double-checking.

  3. What about Malwarebytes and ESET for instance?
    Are they both checking for the same thing or can I just use ESET because it is checking for the same stuff Malwarebytes is?

  4. The reason that I use more than one system is because, some 4 years ago, I had a stubborn virus/trojan which none of the ‘big’ names could remove until a local introduced me to SUPERAntiSpyware which dealt with the intruder 100% efficiently. After that I realised that all of those folk who say you only need one antispyware, etc., are wrong. Since then I have added Malwarebytes of course because everybody says one should but a little mentioned protection, in the form of Threatfire, is a wonderful, lightening fast, system which warns a user immediately it suspects an intruder.
    For good measure I added Spybot because, again, so many pundits insist that it’s the ‘cat’s whiskers’ but I would remove that first if I had to because I really do not understand it. All four systems I hasten to add work perfectly together.
    By the way – all are free which is another reason.

  5. You only need one of the large antivirus programs. Hate to break it to all of you that are using redundant programs but all the smaller companies do, is take the updates sent out by norton, microsoft and kapersky and copy the signature files to update their programs. You’re just wasting memory and getting false positives with junk av programs.

  6. I work for a small company with 15 locations. The employees are very skillful at finding any way possible to infect the computers with spyware and malware. Up until a few years ago I could deal with it using free programs. That’s no longer the case. The malware has become so embedded and difficult to remove that it has become imperative to block it, not deal with the problem after the fact. Based on this experience I rarely bother with free programs anymore but instead use one of the big name programs. I’m fortunate because the ISP we use at most locations provides 25 copies per location of this big name program. Thus my recommendations for people are to check with their ISP and see if the ISP provides a security package with the internet subscription, if it’s a good one, I recommend using it. Otherwise my recommendation is to buy a program from one of the big players in the security world. They’re not that expensive. In the North East US Comcast, Verizon, and Fairpoint include security packages with their subscriptions. I don’t know about any others.

    No sense in using a free program if you are paying for a good quality commercial package from your ISP.


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