I'm running a Norton 2007 on my system but it is terribly slow. It takes ages to get to the desktop. Are there any good antiviruses out there? I've heard of BitDefender,Kaspersky and Avg?How are they? I'm preferabley looking for an antivirus that doesnt affect system performance and also keeps its notification popups to the minimum...

I've been using ESET Nod32, for year now.
It's fast and there's only popups when it updates it's virus databases (you can disable notifications).

Currently it uses around 30 MB of memory (1 GB total and running Windows XP Pro).

It scans files your browser access, so if there's virus or other malware in the page, it'll terminate the connection to page.

There's email protection too.

I agree with Wilhelmus, ESET Nod32 has been great so far.

how is bitdefender??...ive heard its good too...

I have found Kaspersky 7 to be great and use less resources then even NOD32. Right now the two AVP processes are consuming about 15 MB.

As for effectiveness, here is one comparative from when KAV was beta.

oh even i had kaspersky before....but it kept asking for virus definition updates...and it kind of slowed down my system...i think ill stick wid bitDefender...its been good so far...

I am still using Norton version 2003, with updates. It has an option to scan-on-access, as opposed to a full-system scan on startup. The former is relatively fast, since it only scans files when you try to use them (read, copy, move, execute). I then schedule a full system scan for once a week, just before going to sleep.

You might see whether your version of Norton can be made to do something similar.

Otherwise, my only advice is to avoid McAfee, which I am forced to use at work. It is even more cumbersome than Norton.

If you do stick with Norton, my advice is to stay away for the packaged suites, as long as you know what you're doing. From my experience, these suites are really for the common user who is not very Internet savvy, much like people who still use AOL.

It's great for controlling content for a family or if you know very little about what's going on. However, I found them to be incredibly annoying and resource intensive. Just a heads up.

AVG Anti-Virus
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Well, NOD 32 i think whit my personal expierience has been the most effective tool against all kind of virus troyans malware and stuff, it will not bother you whit a lot of pop up screens while you are surfing on the net and it will have your system running smoothly.. somebody from down here says kapersky doesn't use too many resources, when i try to use kapersky hundred of pop up has fill up my screen and make you think is catching virus troyans and malware as you are in a minefield and of course loading your resources to the maximum.Dont believe what magazine says cause they get pay for those advertise...its just that... get your own expierence trying every single tool the you can have access to it and you will find was fit best for you.a

Good luck!!

There are lots of good AV programs out there. NOD32 has been among the top five for a long time with some of the best detection of new threats out there, but it is a commercial program. Kaspersky has been among (if not THE best) the best against known threats for about forever, but I don't think there is a free version any more. Norton is up there in both known and new threats and they claim to have reduced it's bloatware status in the latest version re. system resources and general slowing things down. IDK whether they have toned down their irritating arrogance yet though - that's a good part of why I haven't used it for years. Avira's AntiVir is also at the top and good on both old and new threats. I think it has been up in or near the top 5 for a while and it's still free. I've been using TrendMicro (like PC Cillin) that comes with VCom/Avanquest's SystemSuite and haven't had any infection's that I'm aware of, but that may largely be due to my knowing what to look for and avoiding same.
. A good firewall and running a couple of the good anti-spyware utils out there as well as the one that comes with SystemSuite seems to keep my confuser clear.

.bh.

I recommend kab7 too. I found it has more stable and function than others.

If you want a free antivirus get Avast Home Edition been running it for over a year now, Best one out there. Try it