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
    2014-04-29T21:53:35+00:00

    it keeps graying out the areas as if I am not the administrator. When I dug deeper to check my permissions I'm ok for all but the special permissions. As I went further it says they have to be changed by a trusted installer and it did give me access to change that but it won't accept my name or administrator. What do I do now?

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  2. Anonymous
    2014-04-30T05:28:17+00:00

    I have the same problem and I got error messages saying something is installed and bc of that it cant turn on and I have no security software in my laptop

    what do I do?

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  3. Anonymous
    2014-04-30T10:21:05+00:00

    I have the same problem and I got error messages saying something is installed and bc of that it cant turn on and I have no security software in my laptop

    what do I do?

    What *was* the prior security software?

    You may need to use a cleanup tool to remove your prior security software. See this

    Wiki article: List of anti-malware product removal tools

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  4. Anonymous
    2014-05-05T08:50:06+00:00

    method 1 does not work. Get error message 577, windows could not start windows defender service.

    method2 .I don't have a windows defender icon on start screen.

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  5. Anonymous
    2014-05-05T10:14:50+00:00

    method 1 does not work. Get error message 577, windows could not start windows defender service.

    method2 .I don't have a windows defender icon on start screen.

    Windows Defender on Windows 8 - Introduction and Frequently Asked Questions

    http://answers.microsoft.com/en-us/protect/forum/protect\_defender-protect\_start/windows-defender-wont-start-in-windows-8-after-a/c5fdc22d-3b62-44cc-8485-4a3955b8985a

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