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
    2015-10-24T18:20:39+00:00

    Never mind, I gave up on 8.1 and installed Win 10. Defender started right up.

    Cheers and bye

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  2. Anonymous
    2015-09-18T12:21:52+00:00

    if you turn off all  your other  protection for your virus,spyware,trojans,worns or any other thing that might get in computer and infect it then Defener will turn on i know because i did that.

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  3. Anonymous
    2015-09-18T12:11:25+00:00

    I had windows 8 and 8.i and had the same problem with both, but I found that disabling all virus protection and then turn on Defender it worked after that. then turn your Virus protection back on.

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  4. Anonymous
    2015-09-18T06:31:07+00:00

    my properties to type in automatic and apply is gray out.  no can do.  please help

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  5. Anonymous
    2015-09-17T09:52:34+00:00

    Hi, 

    I have same issue. I tried also both options but still I cant download any security updates or turn the Windows defender on... I have tried on safe mode ---> same error message. Also tried to get updates for definition file manually --> same issues (in both, Admin and User mode)

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