Connecting to the Internet is a two-way street. Not only can your PC access other computers online, but other computers can also access your PCu-4064'3fto access your private data or damage your system hardware and software. You protect against attacks with a firewall program, such as the one included in Windows XP.

1. Click the Start button and select Connect to, Show All Connections.

2. Click Change Windows Firewall Settings.

   

3. Click the General tab.

4. Check the On option.

5. Click OK.

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Other Firewall Programs

Many third-party firewalls offer more protection than the Windows Firewall. These programs include BlackICE PC Protection (blackice.iss.net), Sygate Personal Firewall (www.sygate.com), and ZoneAlarm (www.zonelabs.com).

A computer virus is a malicious software program designed to do damage to your computer system by deleting files or even taking over your PC to launch attacks on other systems. A virus attacks your computer when you launch an infected software program. Here are some tips for protecting your system from computer viruses.

1. Don t open email attachments from people you don't knowu-4064'3for even from people you do know if you aren't expecting them.

2. Don t click links sent to you from strangers in emails, via instant messaging, or in a chat roomu-4064'3feven if the messages appear to be legitimate.

   

3. Do download files from reliable websites only, such as Tucow (www.tucows.com) and Download.com (www.download.com).

4. Do install and use antivirus software, such as Norton AntiVirus (www.symantec.com) or McAfee VirusScan (www.mcafee.com).

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Email Attachments Are Bad!

The single largest source of computer viruses is infected email attachments. If you remember nothing else from this chapter, remember this: Never open an unexpected file attachment, even if it's from someone you know. Period!

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Update Your Antivirus Program

Whichever antivirus program you choose, you'll need to go online periodically to update the virus definition database the program uses to look for known virus files. New viruses are created every week!

If you're like most users, well over half the messages delivered to your email inbox are unsolicited, unauthorized, and unwantedu-4064'3fin other words, spam. These spam messages are the online equivalent of the junk mail you receive in your postal mailbox, and they're a huge problem.

1. Don t post your primary email address in public forums, on message boards, in blogs, or on your web page.

2. Do install and use an anti-spam program, such as Norton AntiSpam (www.symantec.com) or SpamKiller (www.mcafee.com).

   

3. To block future spam messages in Outlook Express, start by selecting the unwanted message.

4. Pull down the Message menu and select Block Sender.

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Use a Spamblock

To confuse email address-harvesting software, you can insert a spamblock into your address. For example, if your email address is [email protected], you might change the address to read [email protected].

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Use Two Addresses

Another trick is to use two email addressesu-4064'3fa public one you use when you post on the Web or register on websites and a private one you give out only to friends and relatives.

Another growing nuisance is the proliferation of spyware programs. These programs install themselves on your computer and then surreptitiously send information about the way you use your PC to some interested third party. Spyware typically is installed in the background when you're installing another program, or when you visit certain websites.

1. Don t use peer-to-peer file trading networks; their software is often infested with spyware.

2. Do install and use an anti-spyware program, such as Microsoft AntiSpyware (www.microsoft.com/athome/security/spyware/software/) or Ad-Aware (www.lavasoftusa.com).

Although they're not dangerous, pop-up ads are extremely annoying. Fortunately, the latest version of Internet Explorer contains a pop-up blocker that effectively keeps those annoying ads from popping up while you're surfing the Web.

1. In Internet Explorer, pull down the Tools menu and select Internet Options.

2. Click the Privacy tab.

3. Check the Block Pop-ups option.

4. Click OK.

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Don't Go Phishing

Another potential problem is that of online identity theft, which can happen if you respond to “phishing” emailsu-4064'3fmessages mocked up to look like legitimate notices from your bank or other institution. When you click a link to update your personal information, you're taken to a phony website and your info is stolen. Avoid the problem by never clicking links in email messages!