This policy setting prevents the user from changing the level of pop-up filtering. The available levels are as follows: High: Block all pop-ups. Medium: Block most automatic pop-ups. Low: Allow pop-ups from secure sites.If you enable this policy setting the user cannot change the filter level. You can specify the filter level by importing Privacy settings from your computer under Internet Explorer Maintenance.If you disable or do not configure this policy setting the user can manage pop-ups by changing the filter level.You may also want to enable the "Prevent managing pop-up exception list" and "Turn off pop-up management" policy settings to prevent the user from configuring pop-up behavior.
Windows Components\Internet Explorer
At least Internet Explorer 7.0