mine started 6 years ago when i first got my own computer and after a day of having it, it had tons of trojans and i was using avg at the time and it did nothing. so my grandad came to my house and installed avast and it cleaned my pc up and since then ive been loyal to it 
I first installed it on an old laptop that had tons of viruses on it, I new nothing about antivirus or anything, so I googled how to remove viruses, and a website said I need to get an antivirus program, so I researched it, and I saw a review that said Avast! was the best antivirus software, and it sure was! Got rid of all those viruses fast! ;D
I just started using it about 2 months ago and so far Iām very pleased. I had used paid solutions from 1999 to 2009 starting with McAfee for about a year and then Norton the rest of the time. I never got infected in all that time but a number of things were caught by the AV I was using at the time. I used Comodo Internet Security with their AV for a year from June 2009 to May of this year but grew tired of all the alerts from a HIPS based product and switched to a combination of the basic Comodo Firewall without the HIPS and Avast! Free AV. So far , so good. I still have yet to be infected since I first got on the 'net 11 years ago.
I abandoned AVG for avast almost six and a half years ago and have never looked back.
i first got my own computer and after a day of having it, it had tons of trojans
how did you manage to do that ???
Winter 2008. I had a virus that kept completely freezing my computer. AVG detected it but my PC froze mid-scan. The scan log was corrupted, and I never detected it again. I eventually took my PC to a repair shop, and they said the hard drive was physically ruined (more recent testing says this may be true). They got me a new hard drive, reinstalled Windows, and put Avast! on it, which I had never heard of, as well as MBAM, and SAS. After I used Avast! for a bit, and started frequenting these forums, Iām confident I wonāt change antivirusā for a long time.
I started using avast three years ago when I heard it from my friend. I was previously using Trendmicro pccillin 2006 which is pretty damn useless against viruses and malware.
Avast caught some hidden malware on the computer, and it was lighter in resources compared to Trendmicro.
Iāve used many AVās before and they werenāt right for me. AVG let in tons of viruses on my old computer, McAfee caused BSODS, Avira kept nagging, MSE didnāt have more options and scans were too slow. Norton was pretty good though. But with avast, Iāve never had a single threat on my computer. Stuck with it for 2-3 years (and will keep doing so ;)). Eventually I upgraded to Internet Security and Iām loving the firewall and the sandbox. ^-^
Remember last July when we were asked to submit a testimonial to Alwil headquarters? I donāt think they ever did anything with them but here is mine:
Back in the Windows 98 days, I evaluated all available FREE antivirus programs. At the time I was using a paid version of a āName Brandā antivirus program on my two computers. At the time, I had determined that if I ever decided to use a FREE antivirus program, avast! would be the one that I would use. I put my notes away and that was it for several years.
I did continue to evaluate avast! from time to time and even joined the avast! forum in December of 2003 to keep up with how avast! was doing.
I finally installed the 2005 version of that āName Brandā antivirus programs on my two computers but began experiencing problems- not the complaints that most people experienced - bloat and bogging down their computers but warning messages like asking me to activate the program which I had done months earlier and also a message that the program did not have a repair feature and that I should uninstall the program and reinstall. A point of interest is that the uninstall program which this company has developed is probably one of the best things they have produced in recent years.
Finally, in late 2006 I received another message telling me to uninstall and reinstall the program. When I began the install process, I received a message saying that I had attempted too many installs and must somehow show proof that I had purchased the program. I had the proof but was so sick of problems with this software that I gave up and installed avast! on my THREE computers. As a side point, I had the 2006 versions of this software which I sold on the Internet for $1.00 US. I pity the persons who bought them.
I now have 5 computers- 4 desktops and one laptop and they all have avast! installed. The desktop that I use the most has avast! Professional installed. I really didnāt have to buy the Pro version since I am a hobbyist but I like the added features and also wanted to say thanks to the folks in the Czech Republic.
Needless to say, I am extremely pleased with the results I have gotten from avast! and something very drastic would have to happen before I would ever change my mind.
I think that the friends to whom I have recommended avast! would agree with me.
Thank you avast!
Itās a long storyā¦ Iāve used McAfee (Viruscan), Norton, AVG and then avast since 8 years ago.
As a second opinion Iāve used Avira for a short time.
Iāve used Symantec, Kaspersky, and Avast. Iāve set up countless computers for my friends and family and they all for some reason insist on Symantec even though it is a hog and their machines are so bloated, so Iām trying to spread the word how light Avast is in comparison. I use Avast on all 3 of my machines and I would never go back. 
Edited: typo
A friend referred me to avast and said dont bother about AVG which was the most popular AV
that soon turned out to be true, nearly every computer I installed avast, and needed to have AVG removed
now most of my friends have avast,
and those with pre-installed AV will install avast once their free period is up
Well, I stumbled over it many years agoā¦
Tried it. Liked it. Kept it since thenā¦ 
And most important: I never regretted itā¦!!! ;D
asyn
Similar to a lot of stories.
I had AVG on this computer, once the pre-loaded trial of Norton expired, got a Zolob trojan that installed SpywareQuake, a variant of SpyAxe, a rogue.
AVG detected but couldnāt remove it. I didnāt know what I was doing, Spybot couldnāt stop it, neither AdAware, I had to take it to the shop to be cleaned.
Got it back and there were still remnants. Started to get serious about learning how to prevent/clean these things and joined a famous antimalware site, recently demised unfortunately. (Castle cops.)
The word was, that Avast was amongst the best of the free AVās. Lots of folk posting HJT logs were using AVG, or Norton, not so many had Avast.
The conclusion was obvious. Never looked back, nor sideways. Never felt the need.
This could develop into an interesting thread.
Iāve abandoned Norton for avast almost six and a half years ago and have never looked back as well ;D cause Norton keep asking me for more money >:(
I work in a computer repair shop. We use all kinds of tools to clean virus / malware from systems. The boot-time scan capability of Avast! is a major factor that keeps it at the top of our list of tools to help clean a system.
We also purchased a license for the BART cd, and use that quite a bit for unbootable systems, or when customers are particularly attached to their antivirus/internet security suite and donāt want us to uninstall it.
We are also fairly successful as an Avast! reseller. I do wish the process for purchasing on a customerās behalf was a bit more intuitive. But I think this might be more a problem with āElement 5ā.
OK, now Iāll admit itāthe last paid antivirus I had (besides PRO) was Norton.
I have always said that the Norton uninstall program was the best thing they ever developed. ;D
I understand that Norton is better today but I will never try it.
Why do we, ex-NAV users, hate it?
I donāt hate it at all. I still think Norton products are excellent. I never had a single problem in almost 10 years of using them and always found them easy to install/uninstall and to upgrade. The versions since 2007 will upgrade to the latest version flawlessly without having to uninstall the previous one first. I also never experienced any of the slowdowns attributed to Norton products. My systems always were responsive and trouble free. The only reason I stopped using NIS was that I wanted to see the degree of protection I could get with free products instead of paying $50 a year for a subscription. Another thing Norton has done though is that they include a free upgrade to the latest version of your software in the price of the subscription. Years ago, they didnāt do that. They still offer an excellent product if you are willing to pay for it.
= hate
avast
= love