how do I reinstall windows defender for windows 10

@  MoonLightBae

Meant as a friendly advice: It's never a good idea to tag your question to an older thread like this one here. As you can see the thread is overly long, has by now accumulated 65 replies on 7 pages. Lots of those replies are off topic and/or concern other problems etc.

In case you can't solve your issue by reading and trying the below advices, please do start your own thread (Ask a Question ) and include as many details as possible (see Suggestions for asking a question on help forums and How to ask an effective question ).

Do you have another Anti-Virus program installed?

In case you already uninstalled a previous  (perhaps pre-)installed Anti-Virus program:

Did you also use the specific removal tool, see this List of anti-malware product removal tools ?

If not, then please do so now and reboot.

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In case, Windows Defender still isn't automatically enabled after doing the above:

I'd suggest to run the ESET AV Removal Tool and see if it can detect another AV or leftover traces...

ESET AV Removal Tool

The ESET AV Removal tool will remove almost any antivirus software previously installed on your system.

direct download link: http://download.eset.com/special/eset_av_remover.exe

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Do you use Spybot?

If so, see

Running Spybot and Windows Defender – Windows 10

https://www.safer-networking.org/faq/spybot-defender-windows-10/

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In addition, I suggest to read and try everything here: http://answers.microsoft.com/en-us/protect/wiki/protect_defender-protect_start/problems-starting-windows-defender-in-windows/808253bb-db89-4db9-a4e5-1c91a86489e9

Hi im moonlight,

Ihave a problem with my laptop for the window defender as i show u the picture below here.

As i highlight for that picture, can you help me solve this problem? thanks

Windows Defender was turned off when I installed Spybot Search & Destroy.

I don't think so - unless you turned it off.

Running Spybot and Windows Defender – Windows 10

https://www.safer-networking.org/faq/spybot-defender-windows-10/

When in Control Panel I see the Icon for Windows Defender, when I click on it a message comes back reading Windows Defender has stopped working, If I have another program to protect me search for it in Services and Maintenance where the heck is Services and Maintenance located. It also said why it stopped working.

Defender will not run live, consistently. cp and services of course show the exe as running.