What operating system are you using? Error Code: 0x8007139f indicates Windows 8.
If using Windows 8, be aware that Windows Defender on Windows 8
is not the same as Windows Defender on earlier operating systems. Windows 8 Defender includes anti-virus protection and may be disabled by the installation of a third-party anti-virus program. Windows 8 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 turn Windows Defender On or Off in Windows 8
If you intend to keep a third-party anti-virus like Norton Internet Security, then Windows 8 Defender needs to remain disabled.
Some anti-virus programs may do the same with the earlier version of Windows Defender on older operations systems such as Windows 7, Vista, Windows XP.Turn Windows Defender on or offWindows Defender is turned off or not workingHow to Turn Windows Defender On or Off in Windows 7
Since you are advising Windows Defender service Could not be started...did you check to ensure the service was not stopped/disabled? These are instructions for restarting Windows Defender...How to Start/Stop Windows Defender service
To start (enable) a service
, press the WINKEY + R
keys on the keyboard or click the Start Orb
and in the Open dialog box, type: services.msc
or press Enter
Note: You can also click the Start Orb
and in the Search Box
, type: services.msc
Windows Services will open:
- Click the Extended tab at the bottom to view all the info on your services.
- In the Services applet, scroll down the list and find the Windows Defender service.
- Double-click on the name of the service to open the Properties page.
- In the Properties Window > General Tab that opens, click the "Start" button if it is stopped.
- From the drop-down menu next to "Startup Type", click on "Automatic".
- Click "Apply", then "OK" and close any open windows.
Note: If your system is Windows 7 or older, I recommend leaving Defender disabled and installing a more effective program like Malwarebytes Anti-Malware