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Batten Your PC's Hatches

Feel as if your PC is under siege? In addition to installing antivirus and firewall software, there's a lot you can do to guard against intruders. Follow this list to help secure your PC.

Disable File Sharing: File sharing lets networked computers pass documents back and forth, but it also lets strangers steal files from your PC over the Net. Consider enabling file sharing only when you need to give someone access to files, and then disabling it afterward. And use password protection for shared files so that only the person you designate can read them.

FIX: To disable file sharing, go to Start, Settings, Control Panel, Network, Configuration, File and Print Sharing. Make sure the option boxes are not checked and then click OK.

Bolster Your Browser: The Web harbors bad code that can exploit your browser's ability to run scripts.

FIX: Adjust the security in Internet Explorer or Netscape Navigator. You can change IE's security via its sliding bar (depending on your version of IE), or you can choose specific functions to control. To use the sliding bar, go to Tools, Internet Options, Security. Select Internet Zone, click Default Level, and move the bar from Low to Medium or High. Low provides almost no protection from Web hazards; Medium disables many scripts but allows cookies; and High disables virtually all scripts and cookies. To set specific functions, select Custom Level and set controls one by one. Be warned: This is more complex. In Netscape, choose Edit, Preferences, and then Advanced in the Category window.

Configure Outlook and Outlook Express: Outlook allows you to disable macros in e-mail attachments or to let some macros through--such as those that are digitally "signed" by trusted sources. You can also have Outlook adopt the security options you define in IE. In Outlook Express, you can set e-mail security levels based only on the settings you've chosen for IE's Internet and Trusted Sites Zones.

FIX: To allow Outlook to let only trusted macros through, go to Tools, Macro, Security and click High. Then, to ensure that Outlook is using your IE security settings, click Tools, Options, Security. You should see the Internet Zone icon in the Secure Content list box. While you're at it, click on Attachment Security and make sure it's also set to High.

Display File Extensions: Many viruses have an extension to the file name, such as .vbs (Visual Basic Script), or a double file extension, as in AnnaKournikova.jpg.vbs, that tips you off. But the default setting in Windows hides them, so you're tricked into opening a malicious attachment.

FIX: Display full file extensions in Windows Explorer by clicking Tools, Folder Options. Select View and check Show all files (in Windows 9 x) or Show hidden files and folders (in Windows 2000 and Me). Some extensions are visible only with a Registry tweak. You can see even those extensions by installing a free copy of Extension Manager. Then, before opening any attachment, right-click the message in your in-box and click View Attachments (but don't click the attachment). If the file has two extensions, it's probably up to no good. If the extension is .bat, .com, .exe, .lnk, or .pif, it is an executable file and may attack your system.

Patch Holes: New security holes are constantly being uncovered in operating systems, browser programs, antivirus scanners, and applications. Don't be caught with your system open.

FIX: Install the latest patches from software vendors. Our next page, "Essential Patches for the Worst Security Holes," details these.

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