How to Avoid Getting a Computer Virus or Worm on Your Windows PC

1. Be careful about using MS Outlook. Outlook is more susceptible to worms than other e-mail programs, unless you have efficient Anti-Virus programs running. Use Pegasus or Thunderbird (by Mozilla), or a web-based program such as Hotmail or Yahoo or 'Outlook Express'.
2. Install an Anti-Virus program(ex. Norton, F-Secure, Sophos or McAfee.) Also available is the free AntiVir virus scanner. Make sure you keep your virus definitions updated and run a full system scan weekly.
3. Install an Anti-Spyware program(ex. Adaware SE, Microsoft Defender), that operates against internet malware and spyware. Just like Anti-Virus, keep it updated, and do a full system scan weekly.
4. If someone sends you an attachment in e-mail or instant messaging, do not open it. If it is a picture, text or sound file (these attachments end in the extensions .txt, .jpeg, .gif, .bmp, .tif, .mp3, .htm, .html, and .avi), you are probably safe. If someone you know very well sends you a Word attachment or other type of file, e-mail them to ask them if they meant to send it to you. If they say yes, you can open it, but you might still be at risk if they are not good about running Anti-Virus scans or careful about what they download. Be wary of attachments with a double extension, such as .txt.vb or .jpg.exe, as the system will only recognize the extension to the extreme right, and run the file as such. Double extensions are often a good indicator that the file is malicious.
5. Do not use disks that other people gave you, even from work. The disk could be infected with a virus. Of course, you can run a virus scan on it first to check it out, but AV programs are not 100% effective.
6. Do not download software from just any old website. If it is a reputable site that you trust, you are probably safe. The threat is not only from software; don't download Word documents or other non-HTML files that have something other than one of the extensions listed above, either.
7. Set up your Windows Update to automatically download patches and upgrades. This will allow your computer to automatically download any updates to both the operating system in Internet Explorer. These updates fix security holes in both pieces of software.
8. Consider switching to a different web browser. Other web browsers (such as Firefox or Opera) are considered to have better security than Internet Explorer; some people also see them as more flexible and extensible browsers.
9. Be careful when surfing. You can get a malicious script from a webpage and not know it. If you have your IE set up for the maximum security settings, you are probably safe. You can try disabling javascript, but I'm not sure if this will entirely help, and it will make your web browsing pretty boring. If you ever get a window asking if you want to allow an automatic install, say "No" unless you know the site requesting the install. Also, don't go to any porn sites. Those are almost always viruses.
10. Read about the latest virus threats so you are aware of the potential danger. Go to Symantec's page to read about them daily.
11. Try to balance paranoia with common sense. Some people get really weird about viruses, spyware, etc. It's just a computer! Back up your data and follow these steps, and it shouldn't be a big problem. Some people would suggest that you make sure you have a firewall and run anti-spyware programs as well. I'm not sure either of those will protect you from viruses, but they will protect you from hacking and from spyware. Microsoft's Antispyware and Ad-Aware are the best anti-spyware/virus programs I have found. Good luck!
12. Use a software firewall! Even if you have a hardware firewall, always use a software firewall (ex. Norton, Mcafee, there's also free ones- ZoneLabs ZoneAlarm).
13. Scan things you download! Now don't be a total nut with this. But if you download something from a site that you don't know/trust, then scan it before opening it. Anything you get from P2P software you should scan, as you are getting it from a stranger. Balance scanning things with number 11, don't go nuts scanning everything you download.
14. View the files in a Sandbox[1]

Posted in: Windows