Windows Defender in Windows 8.1 Will Not Turn On

I am running windows 8.1 and the defender is turned off, I have gone to Action center and I do not find any way to turn Defender on??

Hi,

I think it's because the service is now under action centre. windows 8.1

Go to windows action centre (just search in the new windows start menu)

Enable spyware/firewall protection.

That s it. I assume this will help you

Rajeev

could you be more specific? ...

control panel > ? (what area is the action center in) > windows defender

I am not able to turn on my windows defender 

1. My windows 8 pro did not come with antivirus software ... I built this system myself ... I downloaded and installed windows defender ... it worked great until I updated to windows 8.1 ... 

I just tried turning it on and it says "This app has been turned off and is not monitoring your computer. If you are using another app to check for malicious or unwanted software, use action center to check that apps status".

Yes I also tried it in admin mode. still get the same message ... Nothing allows me to turn it on or off ... not even in action center ...

Edit: It should also be noted that the methods that people keep posting about how to click windows defender and turn it on do not work ... the pop up that you see in the picture above is all that ever comes up ... no matter where or how I access windows defender ... 

This issue only existed after updating to 8.1 ... 

Also in reference to another post ... the firewall protection is not windows defender ... action center says it is on and working ... even though windows defender is not on and not working ...

Final Edit: This should help allot of people ...

I noticed a post from another site that mentioned typing "security" in the windows search charm ... then clicking on check "security" ... this option did not work for me ... there appears to not be anything about security (in reference to windows defender) on this computer ... 

I went and installed bitdefender ... did a full system scan ... It found none of the viruses or spyware ... (the new version of it is very poor) ... I then unistalled it and it prompted a computer restart so I did

Bam! the action center notified me of an issue ... I checked the issue and it told me my computer was not protected and windows defender was turned off. then asked if I wanted to turn windows defender on ... Uh ... Yeah ... now it works and allows me to make changes to it ... 

so If you are having problems with security I would recommend installing something like BitDefender run a quick scan or whatever you can get to work ... turn off your computer then turn it back on ... (not a restart) ... then uninstall it using the uninstall software feature in the control panel ... (this should automatically use that programs uninstall function) ... whether or not it prompts for a restart you should then restart your computer ... then follow the action center prompting ... hope this works for you ...

When I try to turn Defender on in the action center, it takes me to the "system 32" folder and does nothing else.

I have read the entire forum and have not found anything that works.

The firewall is enabled and I have the latest system updates.

I am experiencing similar problems to Jennifer. I have uninstalled all the previously factory installed virus software using the Mcaffee removal tool, I have gone into services and gotten the 577 error, I have tried running Windows Defender from the command prompt in hopes that it would shake something loose, but still no Joy.  What in the world is preventing Windows Defender from starting back up?  Should I reinstall windows 8.1?   It really shouldn't be this difficult, but it is.

To prevent software conflicts, performance issues and reduced efficiency of the affected antimalware programs, Windows Defender is disabled on Win 8 when third party antimalware programs are installed on Win 8.

When you purchased the laptop it probably had a trial version of an antivirus program installed.  Did you uninstall that program and use the appropriate software removal tool and then reboot the computer?

List of anti-malware product removal tools

Recommend you thoroughly review  

Windows Defender on Windows 8 - Introduction and Frequently Asked Questions

Did you use the Lavasoft Removal Tool?  If not suggest you run it and reboot the computer: http://www.lavasoftsupport.com/index.php?showtopic=28

I have not used Lavasoft in many years and know very little about it - do not know when it will be compatible with Win 8.1.

You may need to restart the Security Service and then enable Windows Defender after removing Lavasoft.

For further information about antimalware products see the following:

http://www.dslreports.com/forum/r28298407-2013-Anti-Virus-Poll-

http://www.av-comparatives.org/

http://www.opswat.com/about/media/reports/antivirus-august-2013

And

See the following compliments of quietman7 MS MVP: **Choosing an Anti-Virus Program**

Regards....