Cookies are small pieces of data that websites use to store information on your computer. "Bad" cookies can be used to track a users Internet usage. Rather than remove them after they have been stored on your computer you can choose to block them.
We recommend that you disable all third party cookies. This stops them arriving so you do not have to remove them later.
To undo these changes, the appropriate settings within the affected browsers can be used. These are, for example:
Mozilla Firefox and most clones: type about
:config into the address bar. Confirm that you want to continue editing settings. Enter network.cookie.cookieBehavior into the filter box. Double-click and change the value to 0 to get the default behaviour back. All possible settings are explained at mozillaZine