The NAI has created a global opt-out system in cooperation with its member ad networks. This solution has been tested on various browsers, platforms and operating systems. However, Web-based tools are not flawless.

The performance of the global opt-out tool might be affected by a number of factors outside the control of the NAI and/or its member ad networks. These factors include corporate network security, telecommunications breakdowns, browser settings, ISP or infrastructure anomalies and client-side technical glitches, among other possible issues.

If you experience technical difficulties during the opt-out process, we ask that you first try again. You may also try to opt out directly from any member ad network by clicking its link on the opt-out page.

In order for the opt out to work, your browser must be set to accept 3rd party cookies. Visit the links below for instructions on how to adjust your browser settings.

Internet Explorer 7.x and Internet Explorer 6.x: http://windows.microsoft.com/en-US/windows-vista/Block-or-allow-cookies

Chrome: http://www.google.com/support/chrome/bin/answer.py?hl=en&answer=95647

Firefox: http://support.mozilla.com/en-US/kb/Enabling+and+disabling+cookies

Safari: http://docs.info.apple.com/article.html?path=safari/3.0/en/9277.html

If you continue to experience problems, you can submit an email to the NAI. Provide as much information as you can, including operating system (Mac or Windows), Web browser, error messages, etc.

The NAI Opt-out Tool is cookie-based. In order for the Tool to work on your computer, your browser must be set to accept third party cookies. If you buy a new computer, change web browsers or delete this cookie, you will need to perform the opt-out task again.

Attention Safari users: Apple presets the Safari browser to block cookies from sites other than those you visit directly. As a result, the NAI Opt-out Tool, which uses third-party cookies, will not work for browsers left in this default setting. Click here to review your options.

Attention Internet Explorer 7 users: Yahoo! has a security path that allows IE7 to block its ad network (third-party) cookies when a user's browser privacy setting is set to "Medium High" or "High." As a result, the NAI opt out tool, which uses third-party cookies, cannot place an opt-out cookie for browsers in this setting. Click here to review your alternatives.