Forum Moderators: phranque
Here's what I do - use at own risk :)
In addition to installing reliable anti-virus (AV) software, and most importantly to config it to load ALONG with everything else as your machine boots up, there are a few easy steps that will greatly diminish the possibility of a virus even getting as far as your machine.
If you are using Outlook Express as you local mail client, open it up and go to Tools > Options > Security and check the box that says something like "do not allow attachments to be saved or opened that could potentionally be a virus." Also, it's wise to only accept text messages. Most viruses/worms/trojans/etc will be included in HTML email.
Next, if you use Internet Explorer as you browser, go to Tools > Internet Options > Advanced, scroll down and uncheck both "Install on demand" listings. Click OK, then open Security and click Custom Level. "Download Signed Active X" is best promped so you can decide on a case by case basis what programs you are willing to let others run on your machine. "Download Unassigned Active X" is safer to disable since the source is not willing to be accountable.
I find it a nice combination at work and home.
Opera + any email client not made in Redmond WA with a personal policy to devnull all email attachments that aren't images.
That will protect you from 99+% of the viruses and system exploits on the net today. I feel it's actually a higher level of protection than most antivirus programs.
I've never used any virus protection - never had a virus on my machines. And you know mine are on 24x7 and surf a couple k pages a day and get a 4 figure emails a day.
I have done a good number of virus recoveries/repairs for clients. Some infections even when the virus def's where about a month old. A single virus can ruin your whole day/week and scrap many many hours of work.
IMO the virus creators are evil and need a proper education. (Thoughts of a good rope and 20 miles of dirt road....).