Windows Defender in Windows 8.1 Will Not Turn On

Anonymous
2013-11-24T01:31:23+00:00

I recently updated Windows 8 to Windows 8.1.  Windows Defender had been on in Windows 8 and even after the update to 8.1.  I turned it off momentarily but have been unable to turn it back on.  To my knowledge, I have no other anti-virus programs running.  How can I turn it back on?

Windows for home | Previous Windows versions | Security and privacy

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  1. Anonymous
    2015-08-06T12:29:15+00:00

    After Both Method now em able to run window Defender after Scan.Nice & Thanks BuddY LoVe U...!

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  2. Anonymous
    2015-08-26T15:29:23+00:00

    Neither of these suggestions worked.  I got error messages that they did not work because Defender was turned off.

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  3. Anonymous
    2015-08-26T22:56:51+00:00

    I haven't had Defender for almost a year since I purchased my Windows 8 and upgraded to 8.1.  What can I do to defend my computer from daily attack?  I have purchased independent non successful product to do the job without success so now I am always on the defence for virus attacks.  What can I do?

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  4. Anonymous
    2015-08-27T03:02:47+00:00

    Uninstall all 3rd party antivirus tools you have used, using the cleanup tools provided by the vendors.

    See this Wiki article: List of anti-malware product removal tools

    Windows Defender should then become active or you'll get an alert to take action to enable it.

    Windows Defender on Windows 8 - Introduction and Frequently Asked Questions

    Problems starting Windows Defender in Windows 8/8.1/10

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  5. Anonymous
    2015-08-29T11:44:54+00:00

    I have the same problem. I tried the app removal tool but it found nothing to remove. So how do I turn Defender back on?

    I have searched my pc and find no other anti-viral app but even running as administrator I cannot get Defender back on.

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