This policy setting allows you to manage whether the listed processes respect add-on management user preferences (as entered into Add-on Manager) or policy settings. By default only Internet Explorer processes use the add-on management user preferences and policy settings. This policy setting allows you to extend support for these user preferences and policy settings to specific processes listed in the process list.If you enable this policy setting and enter a Value of 1 the process entered will respect the add-on management user preferences and policy settings. If you enter a Value of 0 the add-on management user preferences and policy settings are ignored by the specified process. The Value Name is the name of the executable. If a Value Name is empty or the Value is not 0 or 1 the policy setting is ignored.Do not enter Internet Explorer processes in this list because these processes always respect add-on management user preferences and policy settings. If the All Processes policy setting is enabled the processes configured in this policy setting take precedence over that setting.If you do not configure this policy processes other than the Internet Explorer processes will not be affected by add-on management user preferences or policy settings (unless "All Processes" is enabled).
Windows Components\Internet Explorer\Security Features\Add-on Management
Machine
At least Internet Explorer 6.0 in Windows XP with Service Pack 2 or Windows Server 2003 with Service Pack 1
HKLM\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl!ListBox_Support_FEATURE_ADDON_MANAGEMENT; HKLM\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_ADDON_MANAGEMENT
inetres.admx