I’ve written a number of times about the need to secure your computer with a good anti-virus program, a good two-way firewall and a good anti-spyware program.
Whether you want to use an anti-spam program is up to you, but if you don’t use the other three, you can become part of the problem. You innocently may visit a web site that infects you with a downloader or another program that subverts your computer via a flaw in Windows or another program.
An additional way to protect yourself, if you have a cable, DSL or Ethernet connection (say, in a dorm room), is that you can use your own router.
Even if you have only one computer to connect, I recommend that you use a cable/DSL router. A router will isolate your computer from the Internet so that no computer on the Internet side of the router can initiate communications with your computer. They can respond to communications from your computer, but they can’t touch your computer except in response to your computer’s communication.
This protection is very important when it comes to operating system flaws. It’s all well and good to have an anti-virus, anti-spyware and a firewall program — but they all count on the operating system working the way it should. We’ve had Windows flaws in the past that enabled computers to be attacked successfully before those protections even came into play.
If you aren’t using wireless communications for a home network, you can buy a probably-cheaper wired router to protect your computer. If you’re using wireless at home, you probably already have a router. Be sure to use a wireless router for your network instead of the much less secure peer-to-peer wireless networking. Many of the security features of wireless communications require a router and don’t work in peer-to-peer mode.
If you are using a wireless router, you should secure your network. You don’t want to share your computer’s files and printer with everyone in your neighborhood. More importantly, in order to share files and printers among computers on your network, you will probably have to tell your software firewall to "trust" at least part of the network. Of course, anyone connecting to your router wirelessly will also be assigned one of the trusted IP addresses, so you will have let down your guard.