Many folks use anti-virus software that comes bundled with their computer. It may have a "free" trial version and then you have to pay $39.95 a year to keep it up. Do Norton and McAfee work? Yes, they do, but they are expensive. Do they slow down your computer? Some folks claim they do, and others claim that McAfee is actually, according to the definition, spyware.
People are paranoid about computer viruses, worms, trojans, and the like - and they should be. There are a number of free bits of software out there, which when used in conjunction with web-based e-mail can provide you with a very good level of protection. Combined with safe surfing practices, the odds of getting a computer virus are slim.
However, you have to use ALL of the following, not just bits and pieces!
1. Safe Surfing: Most computer viruses, trojans, and worms require some action on the part of the user to activate. Unless you have your browser set to auto-launch .exe files, chances are, a rogue application cannot start on your computer without you doing some action first.
Thus, for example, a pop-up appears suddenly, saying that "Windows has discovered a virus! Click here to eliminate!" - your "click" is actually the action that loads the virus and the message you read was bogus.
Avoiding rogue websites is a good idea - but don't think that just avoiding porn sites is sufficient. Music lyrics sites, for example, are often loaded with Trojans - which will pop up that fake virus message previously noted.
I find trojans sometimes in sites purporting to have IEEE publications (articles relating to electrical engineering). Hmmm... why do you suppose they would use an IEEE publication as bait? To get after high tech computer networks, of course.
So it's not just porn sites that are going to load rogue software. Google and other search engines will often warn you if a site may have malware, so loading a site through Google is often a good idea.
Typo sites - like Faceboook.com (too many o's) or Facebok.com (not enough o's!) may load up "surveys" and put up graphics that LOOK LIKE Facebook, but are not. If you fall for this bait, you likely will get dinged. BOOKMARK your popular sites and use the bookmarks to avoid logging into rogue sites.
By the way, these "online surveys" are a con - they ask all this information, including your cell phone number, and then charge your cell phone a monthly service charge for some bogus "service" and you'll never get it off your bill!
Walk away from online surveys, "free screensavers" and other garbage that you don't need - it is usually bait for malware at worst, or just ads at best.
AVOID FORWARDING E-MAILS: You look like an ass, when you mass-forward an e-mail anyway, so just stop doing it. Most are just jokes and such, or political diatribes, or just outright lies (Obama is a Kenyan, that sort of nonsense). But many have virus loads, particularly the "click here" variety.
And if you get an e-mail with a "click here" attachment, even from a friend, avoid clicking on it. The friend's e-mail may have been hacked and the attachment is a virus load. If it is not a PDF or DOC file, do not click on it. E-mail your friend to confirm the e-mail was from them before clicking on unknown attachments.
And if you get an e-mail from "Microsoft" or "Yahoo" claiming your account is going to "expire" unless you "verify" it by typing in your name, address and password, DELETE IT. They DO NOT send out such e-mails. Even if it has all the logos and looks "official", never fall for that old gag.
And NEVER click on a link in an e-mail purporting to go to you banking website or whatever. Instead, go to your bookmarked link and enter the website the normal way. Embedded URL's (Universal Resource Locators) can be masked to look like official sites, but actually be sending you off to a Russian Mafia-run website.
Using this and other safe-surfing techniques will help you avoid 90% of virus, trojan and worm problems.
2. Use Web-Based e-Mail: Web Based e-mail has several advantages over POP server e-mail. If you are using POP server type (accessed through Microsoft OUTLOOK or other "e-mail program") you are vulnerable to Outlook-based WORMS, which, when opened, will scan your mailing list and forward themselves to everyone on your mailing list.
Web-based e-mail is also portable - you can log onto the website anywhere, from anyone's computer, without having to configure a pop server account. And if you move or change ISP's (Internet Service Providers) you still keep the same e-mail address. Why lock yourself into an @Bellsouth.com address when @yahoo is forever?
Best of all, the three main web-based e-mail providers, Yahoo, Hotmail/MSN, and Gmail, all have built-in virus-scanning for attachments. Why pay for mcAfee when Hotmail gives it to you for free?
You can actually PAY for these services, to reduce the number of ads, and obtain extra features (more storage space, etc.)
Which one should you use? I use all three, myself, and have two forward into one, so I have triple redundancy on my e-mail service. I can be reached at robertplattbell @gmail.com, @yahoo.com, and @hotmail.com. But they are all pretty much the same, even to the point of using the same software.
Google Gmail offers an online document storage service and a primitive "cloud" computing service - you can create documents in word format in a word-like environment. But other than that, they are all about the same - offering calendar features, etc.
If you use web-based e-mail, you avoid the Outlook worms and get free virus scanning for incoming attachments.
If you think about it, your risk for viruses is from incoming attachments - rarely are viruses preloaded onto your computer! So this step alone filters out 99% of any virus problems.
3. Use a free Malware Detection Software: Spybot is probably the best of these. But make sure you are downloading the REAL DEAL from safer networking at:
Many scams and viruses are naming themselves similar names - like spwaredetectbot or something, hoping you will be confused.
RUN Spybot, INSTALL Spybot, and then once a week, UPDATE Spybot and IMMUNIZE your browser and then RUN a malware check. You should also run the "tea timer" which monitors your Windows Registry "Hives" and warns you when a website or piece of software is trying to make a registry change (Windows Vista does this as well, unless you turn it off). Usually, there should be no need to change your registry, and when a website tries to do this - watch out!
Malwarebytes is another program - I run and use both. The FREE version does not have a teatimer, but with SpyBot running, I don't need it. About once a week, I update and run both programs.
Spybot asks for donations. I've send them a few bucks by PayPal now and then. They deserve it.
4. BACKUP Important files: If you have a home network with multiple computers, BACK UP important files to other computers. You need not use special "Backup" software to do so. Just COPY your photos, music and files to other machines. If you are using Gmail, consider copying files to the "cloud". Backup software often backs up and compresses the entire hard drive, which I think is unnecessary - you don't need to make a backup copy of Windows and your other applications. If your machine crashes, you will re-install those anyway.
I have four machines on my network, and I copy my photos, my music, and my documents to all four. This way, three machines can go South and I still have a complete copy available to me.
Small portable hard drives of 500 GB to 1 TB can be had for $100 to $200 or so - and they can be an easy way to back up all of your "stuff" and move it from machine to machine as well.
I have not used a "commercial" virus program in well over five years. If you have Norton or McAffee on your system and are being bugged to PAY for another year's service, you might want to consider the free alternatives. HOWEVER YOU HAVE TO KNOW WHAT YOU ARE DOING AND DO IT. Following the above instructions in a half-assed or incomplete manner is not going to protect you. And if you decide to go this route, you may have to UNINSTALL your McAfee or Norton programs.