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The Web can be a dangerous place. Scripts or ActiveX controls on some Web sites can be intentionally or accidentally harmful to your data. Cookies some sites store on your hard drive may reveal more than you want about your browsing habits. Internet Explorer offers several levels of security, and understanding them can help you make the Internet a safe haven, letting you set just the level of risk you can handle.

To set security levels in Internet Explorer, start by selecting Tools, Internet Options (if you have IE 5) or View, Internet Options if you use IE 4. Next, click the Security tab.

You should be most concerned with the security settings for the Internet Zone. Here's a rundown on what each level of security offers:

High (most secure): Scripts or ActiveX controls on a Web page will not run at all. Cookies will not be stored on your computer, and sound and video files will not play. This is the safest level, almost guaranteeing that no site will damage your data. The downside of this level of security is that it eliminates much of the functionality of advanced Web sites.

Medium (more secure): This is the default setting for typical Internet use. It allows cookies to be stored on your system, but prompts you before downloading potentially dangerous material and will not run scripts or ActiveX controls unless they are certified. This setting is a good compromise for general browsing, letting you make on-the-spot decisions about potentially dangerous content.

Medium Low: This option is only available in IE5. At this setting, cookies are allowed, but sound files and videos will run without prompts and scripts and ActiveX controls without certificates will not run. This level is appropriate for pages on your corporate intranet but poses some risks for general browsing.

Low: This setting offers virtually no protection at all, allowing all scripts and controls to run, with all downloadable content automatically executed by your computer. Unless you have a specific reason for setting your security this low, don't select this level.

You can further customize your security features to exclude certain things permitted in a certain level. In IE 5, click the Internet icon, and then click Custom Level. In IE 4, click the Custom radio button, and then click the Settings button. A dialog box will appear to let you set individual security levels for each feature. To find out what each feature means, right-click the security feature, and pick What's This? for a detailed explanation.