The "Disable toolbars and extensions when InPrivate Browsing starts" machine setting should be configured correctly. enabled/disabled Computer Configuration\Administrative Templates\Windows Components\Internet Explorer\InPrivate\Disable toolbars and extensions when InPrivate Browsing starts HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Internet Explorer\Safety\PrivacIE Microsoft Tool: Security Compliance Manager (SCM) Microsoft Baseline: Internet Explorer 8 SCM URL: http://go.microsoft.com/fwlink/?LinkId=113940 Microsoft Security Compliance Manager (SCM) Baselines and Settings Packs Microsoft