- Click the Tools button, and then click Internet Options.
- Click the Privacy tab, and then move the slider to the level of privacy you prefer.
- Block all cookies will prevent use of any cookies on this or other sites.
- Select the Privacy panel.
- Set Firefox will: to Use custom settings for history.
- Remove the check mark from Accept cookies from sites.
- Click OK to close the Options window
- Click the spanner icon on the browser toolbar.
- Select Settings.
- Click Show advanced settings.
- In the "Privacy" section, click the Content settings button.
- In the "Cookies" section,Select Block Cookies by default
- Select "Block sites from setting any data".