自動更新からスパイウエア対策まで

By James Watt, Freelance Writer

　先月に引き続き、パソコンをウイルスから守るコツを4つのポイントから解説します。

　Last month we talked about how to make your computer less of a target to computer viruses by using free software such as Firefox. One problem is that no matter how small a target you make, if you use Windows you still are at high risk of getting a virus. So, this month, I'm going to show you four things to ensure your computer remains virus free.

1) Constantly update your computer

　Always update your computer when Windows tells you to. In fact, no matter what operating system (OS) you use -- Windows, Mac OS X, or Linux -- when you are told to update: update. Every OS has its own version of an automatic update service, and the default setting is usually on. You should double-check your computer to make sure.

　In Windows XP you can do so by clicking on Start, then Control Panel and finally Security Center. (The process for Vista is similar.) Look at the "Update" button and make sure it is set to automatic. Security Center is a good place to start when you want to check how safe your computer is.

2) Use a firewall

　A computer connected to the Internet is like a house with open curtains and open doors. Anybody who walks by the house can look inside and see everything, and can walk in your front door and start stealing things. A firewall is a basic security device for your PC that basically closes all the curtains and doors in your PC so that no one can see in or steal things. Check Security Center to see if your firewall is on.

　Another problem pops up at this point. What if the thief is inside before the firewall is closed? Or what if you let the thief in by accident when you open the door (e.g., when you check your e-mail)?

　That's what anti-virus programs are for.

3) Anti-virus programs

　I explained what a virus is last month, but it's probably still a bit unclear. A virus is a program that installs itself in your computer and can come in many forms. Because viruses all have different goals and abilities, it's often difficult to say which are dangerous and which are just a nuisance.

　Some viruses are designed to take over many computers and make them access one Web site all at one time. This is called a denial-of-service attack, and it can crash a Web site because too many people are trying to see it at one time.

　Some viruses exist for no reason other than to annoy people. They install themselves in a computer, and then e-mail copies of themselves to everyone in the first computer's e-mail address book where they install and spread again.

　Viruses can even control huge numbers of computers that attack bank or government computer networks. Fortunately, this problem also has a simple solution.

　Buy or download anti-virus software.

　Personally, I'm cheap so I use the free version of AVG Anti-Virus from http://free.grisoft.com/. I haven't had a virus since 2004, so although it's free, I know it works. You could also buy an anti-virus program such as Norton from your local electronics store, or use the online anti-virus program at http://housecall.trendmicro.com/. All are good. Just make sure you use one.

4) Get anti-spyware

　When you first bought your computer, did it run much faster than now? Does it take longer to open Internet Explorer and e-mail now? Well, you might have spyware.

　Spyware is software that is usually installed after you visit dodgy Web sites or click on unknown advertisements. Any Web site can run it, and you might not even know it's been installed. Spyware doesn't really hurt your computer, but it does affect your ability to use the computer.

　Spyware uses up CPU power (your computer's brain) and Internet bandwidth to send information about what sites you visit to someone else. That's why it's called Spyware. It spies on you. Spyware makes Web sites load slower, and increases your computer's workload, making programs run slower, too. Even with only two or three spyware programs running, your computer can slow to a glacial pace.

　Download anti-spyware software -- such as Spybot-S&D from http://www.safer-networking.org/ or Ad-Aware from http://www.lavasoftusa.com/. They are both free (Ad-Aware has a free version), and the programs are updated regularly. After you run them for the first time, you might notice a big difference in speed.

　Science fiction writer Robert Heinlein (1907-88) popularized the saying "There ain't no such thing as a free lunch." In other words, if you come across something on the Net that looks too good to be true, it probably is. Ignore ads and links that lead to unknown sites, just as you would pay no attention to people trying to sell you things on the street.

　The most important point is this: if you just use the same common sense online as you would in real life, you will be totally and completely safe. Relax, have fun, avoid flashy advertisements, and within two weeks you will be surfing like a veteran.

　Good luck and good surfing.

• default setting　初期設定
• e-mail　e-mailで送信する。動詞
• where　関係副詞。先行詞はeveryone
• dodgy　危険な、インチキの
• bandwidth　回線容量
• glacial pace　氷河の速度。極めて遅いスピードのこと
• it...is　おそらく本当であるにはうま過ぎる話なのだ（本当ではない）