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
    2014-06-23T18:43:36+00:00

    Still won't start. After I removed Norton it's preventing it I think.

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  2. Anonymous
    2014-06-24T02:17:48+00:00

    Still won't start. After I removed Norton it's preventing it I think.

    Defender not starting after removing prior a/v -- Win8: 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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  3. Anonymous
    2014-06-25T20:19:25+00:00

    Tried both options but it did not work. I get an error message when I try to open Defender

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  4. Anonymous
    2014-06-25T21:10:11+00:00

    Tried both options but it did not work. I get an error message when I try to open Defender

    And that error might be?

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  5. Anonymous
    2014-07-25T12:37:12+00:00

    I cannot find Defender from start/run. When I typed "services.msc" I could not open Windows Defender and received error code 577:

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