The Temporary Internet Files section enables you to control the size of the cache (storage area) IE 4 maintains on your local hard disk for holding copies of pages you've visited or subscribed to. Clicking the Settings button opens another page with options to control when IE 4 checks for newer versions of pages stored in your local cache, and allows you set a maximum size for the cache on your local disk (very important, as the cache can grow alarmingly quickly).

The History section lets you limit the number of days for which IE 4 will keep History items, while the Colors, Fonts, Languages and Accessibility buttons control aspects of the browser's appearance when displaying Web pages.

Security Zones are a new feature of IE 4. By assigning a Web site (e.g. www.microsoft.com) to a security zone, you can control the type of special content (e.g. ActiveX controls, Java Applets) which IE 4 will download and run from that site.

IE 4 comes with these four pre-programmed security zones. The Trusted zone is for sites which you're confident have reliable content. Conversely, the Restricted zone is for sites from which you want to prevent download of potentially dangerous content. The Internet zone is the default, containing all the sites you haven't assigned to other zones.

You can set the security level of each zone, either to one of the three pre-set levels (High, Medium, Low), or to a custom level, which lets you decide exactly what restrictions are placed on content from sites in that zone.

To assign a Web site to a security zone, press Add Sites. This opens the Add Site dialog. Tip - to save typing a URL in, select it in IE 4's Address Bar, copy it to the clipboard (Ctrl-C), then open the Add Sites dialog and paste it into the 'Add this Web site...' box (Ctrl-V). To remove a site from a security zone, select it in the Web sites list (top of dialog), and press Remove.

The Content tab lets you control the type of Web page content (images and text, as opposed to software components) which can be viewed on your browser. It also lets you administer the system of digital certificates which enables both you and Web sites to verify that you really are who you say you are. Finally, it lets you store sensitive information, such as personal details and credit card information, in secure form for encrypted transmission across the Internet.

The Ratings section (also known as the Content Advisor) allows you to control access to Web sites according to their RSACi ratings, which are set by the site authors for categories such as language and nudity. You can choose which level of each category (e.g. how bad the language) you're willing to allow on your browser screen. You can also specify that sites which don't have a RSACi rating can't be seen at all. The ratings system is password-protected, and once you've turned ratings on, they can only be turned off using the password. This lets you leave your PC (relatively) safe for others to use. The RSACi rating system is included with IE 4, but you can also add other ratings systems as they appear.

In the Certificates section, the Personal button shows a list of authentication certificates you've obtained from third-party authentication servers to prove your bona fides on the Net - such certificates may be required, for example, by merchant servers before they'll accept orders from you. Conversely, secure Web sites obtain certificates proving who they are; the Sites button shows a list of the authentication servers whose certificates your browser recognises. The Publishers button lists those software publishers (e.g. Microsoft) whose software you allow IE 4 to download and run without asking you first.

The last three tabs of the Options dialog control your connection to the Internet, define which programs you use for ancillary functions such as email and newsgroups, and provide a long list of detailed options for controlling the behaviour of the IE 4 browser.

The Connection tab selects your connection to the Internet. If you're using a dial-up link you'll have the 'Connect using a modem' option set, and can make detailed changes to the connection using the Settings button. These include the dial-up networking connection to your ISP (Internet Service Provider) which you use to access the Net, the number of dialling retries and - a great phone-bill saver - the maximum period of inactive time before IE 4 automatically disconnects the line. You can also tell IE 4 to connect using your stored ISP user name and password - this saves time when dialling, but means that anyone else using your PC can connect to the Net on your ISP account. If your PC is liable to be used by other people, it's best not to leave your password stored in this way.

The Corporate Proxy Server and Automatic configuration sections of the Connection page are for users who connect to the Internet via corporate LANs. If you need to use these options, contact your network administrator for details of what to enter.

Checking the 'Internet Explorer should check...' option at the bottom of the page causes IE to pop up a dialog box if, on loading, it finds that it's no longer your default browser. You can then tell it to re-establish itself. This option is useful if you're installing other browsers, which typically make themselves the default during installation.

Cookies (snippets of data stored by Web pages on your local disk) have had a bad press in recent months - they're not as dangerous as they've been painted (in fact not really dangerous at all), but you may wish to set the 'Prompt before accepting cookies' option.

Leaving 'Print Background colors and images' unchecked will stop IE printing large coloured page backgrounds.

See also Accessibility