Use rsop.msc to check that there is no group policy setting that is applied to disable Windows Defender. More here: http://support.microsoft.com/kb/927367 This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner 2010 / 2011 Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Applications Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows 7, Configuring Microsoft Certified IT Professional: Enterprise Administrator Microsoft Certified IT Professional: Server Administrator

Use rsop.msc to check that there is no group policy setting that is applied to disable Windows Defender. More here: http://support.microsoft.com/kb/927367 This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner 2010 / 2011 Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Applications Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows 7, Configuring Microsoft Certified IT Professional: Enterprise Administrator Microsoft Certified IT Professional: Server Administrator

When I go to open Windows Defender a message comes up that says "Windows Defender is turned off by group policy" What does this mean and how do I fix it?

Use rsop.msc to check that there is no group policy setting that is applied to disable Windows Defender. More here: http://support.microsoft.com/kb/927367 This posting is provided "AS IS" with no warranties or guarantees , and confers no rights. Microsoft Student Partner 2010 / 2011 Microsoft Certified Professional Microsoft Certified Systems Administrator: Security Microsoft Certified Systems Engineer: Security Microsoft Certified Technology Specialist: Windows Server 2008 Active Directory, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Network Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows Server 2008 Applications Infrastructure, Configuration Microsoft Certified Technology Specialist: Windows 7, Configuring Microsoft Certified IT Professional: Enterprise Administrator Microsoft Certified IT Professional: Server Administrator

Hi, If you have Microsoft Security Essentials installed, Widnows Defender will be disabled by default. Regards,Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.