I have had my new desktop for a couple months.  My windows defender had an issue.  I started the program and tried to "start now".  I received a box that stated "The service couldn't be started.  The group or resource is not in the correct state to perform the requested operation.  Click Help for more information about this problem.  Error code:  0x8007139f.

I suspected you have other antivirus program beside Windows defender

remove that other antivirus and turn on defender, or if you still want to use that antivirus, windows defender should be disabled

• Edited by britishdhez 2 hours 38 minutes ago

I suspected you have other antivirus program beside Windows defender

remove that other antivirus and turn on defender, or if you still want to use that antivirus, windows defender should be disabled

• Edited by britishdhez Wednesday, June 03, 2015 4:45 AM

Hi,

Windows 8.1 Defender includes anti-virus protection and may be disabled by the installation of a third-party anti-virus program. Windows 8.1 Defender will remain disabled until the third party anti-virus has been completely uninstalled and then Windows 8 Defender needs to be activated if you choose to use it.

How to enable or disable Windows Defender in Windows 8.1
http://winaero.com/blog/how-to-disable-or-enable-windows-defender-in-windows-8-1/

If you intend to keep a third-party anti-virus like Norton Internet Security, then Windows 8.1 Defender needs to remain disabled.