Mine isn't free, but I've had Eset for a few years now and haven't had any issues.

Another for Malwarebytes. I only download the most recent version every now and again, instal and run it to check for malware, then uninstall till the next time I want to do a scan.

+1 MalwareBytes - I just used it literally yesterday to finish getting crap ware off my son's net book.
 
Bob Bone
 

Install Adblock Plus in your browser and most of the ads that lead to malware sites will disappear.
 
Regards,
Dan

Hi,
 
Been using F-Secure on all my computers for 8 years now, and only had an issue once on a computer that was not clean to start with and I got one of those that goofed around with the registry real bad and even fudged the bios ... since then I make sure the order is correct on each computer .. windows, f-secure, then the windows updates, and then whatever ... but one thing that I recommend is that the "browsing" computer not be the music computer, and in my case, also the writing computer, to prevent further issues.
 
I know some of us can't afford it, but my 4 computers ... is not enough! 2 of those also do regular backups of the folders where my work is.

bitman
Actually, it's you!
 
There is no software that can prevent malware if one constantly clicks on the same sucker stuff over and over. I have made a living from cleaning machines since 93 and they all have every flavor of this and that to "prevent" bites in the shark tank that is the internet.
 
It's always the same two or three people in any office and walk-ins are becoming what we call frequent flyers. For those the only remedy is disconnect. Other that that, quit having "fun" on the net. It's no "fun" anymore.
 
This doesn't sound "cool" but it is the absolute truth man.
 

^^^^^
This
 
Most of the really bad stuff is from people blindly opening attachments or popups you get while surfing telling you it detected this or that needs to be upgraded so click on "I'm just an updater not a trojan.exe". Most of the big corporate hacks started with someone clicking on an executable and letting them behind the corporate firewall.
 
I suppose you could hire a bouncer to look over your shoulder and smack you if you try to do something like this.
 
 
Basic rules:
1. Never open an attachment from anyone you don't know or aren't 100% sure they are who they say they are. Real companies don't send you attachments out of the blue. They also don't send you to insecure sites to deal with login problems and whatnot. If you get an email that there's something wrong with your account, don't click on anything; instead go to the site directly on your own where you will likely find that there is no problem. 
 
2. If a friend sends you an email with a "funny" or "You must see this!" attachment, don't bother. Friends who know anything about security don't send friends unnecessary attachments. And it isn't safe because a friend sent it - it may have been sent by a compromised machine or your friend doesn't know they've been hacked yet.
 
3. Never click on popups. Set your browser to prevent popups and if you're on a legit site that actually requires one you will get a message from your browser to allow it. If you get a popup while surfing, close it with Ctrl-W or the tab bar, not by clicking on the popup itself. Real companies don't need third part sites to keep you up to date.
 
 
It's ridiculously easier for hackers to use human engineering to entice people into allowing them in than it is to spend huge amounts of time exploiting holes over many layers of security that will only work on a percentage of machines and be closed fairly quickly as soon as they are discovered.

Sorry folks. I mistakenly wrote that I use flash blockers when I meant that I use adblocking plugins in the Firefox and Opera browsers. I believe they are important.

Since I no longer have a lot of PC's up and working, I've started a set up where I've got a base OS on an SSD, all data on a separate hard drive and virtual machines (VM's) for whatever I'm working on.  Currently that means a "normal" working PC (Microsoft Office, PhotoShop, email, etc.), a programming machine (Visual Studio 2013, MS SQL, Eclipse, etc.), and an "internet whore" VM.  Eventually I may get my DAW over too, but it's still happy on an old dual 1.3ghz server box (cutting edge vintage 2001 I think - *Sigh...*).  This way, if I do get something from the web that I don't want, I simply delete that VM and restore my "golden copy."
 
Lack of funds for an extra hard drive is slowing this down. My main 3TB drive is the one that got corrupted late last year - unfortunately, thousands of files were corrupted before I even knew there was an issue so my backups also had corrupted files on them...

Another vote for ESET, I also use SuperAntiSpyWare and haven't had anything get through for years.

Be careful where you step, and watch what ya eat,
Sleep with a knife and you got it beat !
 
For me the best thing (I think) has been W7 or W8. XP was vulnerable. I use Norton 360 (I get it free with Comcast internet) on my laptop and between it and W7 64, I have not had a problem. With XP I was removing some sort of malware pretty regularly, I got pretty good at it too. I run CCleaner occasionally and I have Malwarebytes Free but I don't run it in the background, just a scan now and then but it never finds anything bad. I also keep Panicware popup blocker running all the time (it is free too). I think it does a better job that the Windows popup blocker. If I'm not "careful where I step" I get little notifications from Norton that it blocked this or that. It has served me well.
I do think that the biggest help has been the improved OS.