Managing Browser Cookies and Other Temporary Internet Files

Whenever users browse the Web, many types of temporary Internet files are stored on their computers, including:

• Standard temporary Internet files Copies of Web pages, images, and media from sites users have visited

• Browser cookies Used to store information about preferences, log-ins, etc.

• Browser history Lists of Web sites users have visited

• Form data Saved information typed into forms

• Passwords Passwords saved from users previously signing in to Web sites that use forms-based authentication

The most misunderstood temporary Internet file is the browser cookie. Browser cookies are used to store information on client computers so that it can be retrieved in other pages or in other browser sessions. Cookies are commonly used to store sign-in information for protected Web sites, user preferences, and shopping cart items. Internet Explorer browsers save cookies in domain-specific text files. Cookies are read from and written to cookie files as records. Fields in a cookie record detail the domain of the server that created the cookie, the name of the cookie, the string of data being stored in the cookie, the expiration date for the cookie, a Boolean value indicating whether you need a secure HTTP connection to access the cookie, and a path designator indicating the URL path(s) that can access the cookie.

You can manage browser cookies and other types of temporary Internet files using the Internet Properties dialog box. If users spend a lot of time on the Internet and you have disk space limitations, you might need to more closely manage the space used by temporary Internet files. Access the Internet Properties dialog box in Control Panel by clicking Network And Internet and then clicking Internet Options. Afterward, use the following procedures as necessary to recover and restrict disk space usage:

Clear out temporary Internet files

1. On the General tab, click Delete under Browsing History.

2. Delete individual types of temporary Internet files by clicking the related buttons. When prompted, click Yes to confirm the action.

3. Click Delete All to delete all types of temporary Internet files. When prompted, select Also Delete Files And Settings Stored By Add-Ons to delete temporary files and settings created by browser add-ons. Click Yes to confirm the action.

Set disk space usage for temporary Internet files

1. On the General tab, click Settings under Browsing History.

2. Use the Disk Space To Use combo box to specify how much disk space can be used by temporary Internet files.

3. By default, temporary Internet files are stored in a folder under %UserProfile%. If you want to move this folder to a drive with more space, click Move Folder and then use the Browse For Folder dialog box to select the new save location.

4. Click OK twice.

Internet Explorer relies on a Web site's compact privacy policy to determine how the site uses cookies. The World Wide Web Consortium (W3C) has defined an official recommendation regarding Web privacy called the Platform for Privacy Preferences Project (P3P). P3P enables Web sites to report their privacy practices in a standard format that can be retrieved automatically and interpreted by user agents, such as Web browsers. User agents rely on what is reported in the compact privacy policy, and generally cannot determine whether cookies are used as reported.

You can use the Privacy tab of the Internet Properties dialog box to configure the way browser cookies are used. You can then use the Settings slider to specify how cookies should be used. Privacy settings available include: Block All Cookies, High, Medium High, Medium, Low, and Allow All Cookies. When you are using a privacy setting ranging from High to Low, you might want to make an exception for a site rather than raise or lower your privacy setting. To do this, click the Sites button on the Privacy tab. Type the address of the Web site in the field provided and then click Allow or Block as appropriate. If you click Allow, cookies for the site will then be accepted. If you click Block, cookies for the site will then be blocked. Keep in mind that you cannot make exceptions when you use the Block All Cookies or Allow All Cookies setting. With these settings, all cookies are always either blocked or allowed—there is no in between or exception.

The privacy setting options are used as follows:

• Block All Cookies Blocks all new cookies and ensures any existing cookies cannot be read by Web sites. Many Web sites won't function properly if you use a setting of High or Block All Cookies. It is also important to point out that any sites you've configured as Allow exceptions are blocked as well. This means the Allow exception is ignored while this setting is selected.

• High Blocks all cookies from sites that do not have a declared privacy policy indicating the source, purpose, and lifetime of cookies used by those particular sites. It also blocks all cookies with a declared privacy policy stating that those cookies gather information that could be used to contact you (such as your name, e-mail address, home address, and logon information) without your explicit consent.

  Note

  Browsers determine whether and how cookies gather personal information based on the site's declared compact privacy policy. Browsers rely on the policy itself and generally cannot determine whether personal information is collected as stated.

• Medium High Blocks cookies from sites other than the one you are viewing (such as an advertiser who advertises at the current site) that do not have a declared privacy policy statement indicating the source, purpose, and lifetime of cookies used by that particular site. It also blocks cookies from other sites (such as advertisers) with a declared privacy policy stating that cookies gather personal identification information without your explicit consent. Further, it blocks cookies from the current site if there is a declared privacy policy statement that specifies that cookies gather information without implied consent.

  Note

  Implied consent is granted automatically. Basically, it means you haven't opted out or told the site you don't want personal information to be collected, so the information can be collected.

• Medium The default privacy setting. Blocks cookies from sites other than the one you are viewing (such as an advertiser at the current site) that do not have a declared privacy policy indicating the source, purpose, and lifetime of cookies used by that particular site. It restricts cookies from the current site and blocks cookies from other sites (such as advertisers) that have a declared privacy policy stating that cookies gather personal identification information without implied consent.

• Low Blocks cookies from sites other than the one you are viewing (such as an advertiser at the current site) that do not have a declared privacy policy indicating the source, purpose, and lifetime of cookies used by that particular site. It restricts cookies from other sites (such as advertisers) that have a declared privacy policy stating that cookies gather personal identification information without implied consent.

• Accept All Cookies Accepts all new cookies and allows Web sites to read existing cookies. It is important to point out that any sites you've configured as Block exceptions are allowed as well, meaning the Block doesn't apply while this setting is used.