The MK Protocol Security Restriction policy setting reduces attack surface area by preventing the MK protocol. Resources hosted on the MK protocol will fail.This policy setting allows administrators to define applications for which they want this security feature to be prevented or allowed.If you enable this policy setting and enter a Value of 1 use of the MK protocol is prevented. If you enter a Value of 0 use of the MK protocol is allowed. If a Value Name is empty or the Value is not 0 or 1 the policy setting is ignored.Do not enter the Internet Explorer processes in this list: use the related Internet Explorer Processes policy to enable or disable IE processes. If the All Processes policy setting is enabled the processes configured in this box take precedence over that setting.If you disable or do not configure this policy setting the policy setting is ignored.
Windows Components\Internet Explorer\Security Features\MK Protocol Security Restriction
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_DISABLE_MK_PROTOCOL; HKLM\Software\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_DISABLE_MK_PROTOCOL
inetres.admx