Windows 10: Windows Defender Won't Turn On

Discus and support Windows Defender Won't Turn On in AntiVirus, Firewalls and System Security to solve the problem; O.k....Out of curiosity I installed Avast free AV.....then decided to stay with Windows Defender, and so uninstalled Avast......now, Defender won't... Discussion in 'AntiVirus, Firewalls and System Security' started by Del 80, Sep 14, 2017.

  1. DEL 80
    Del 80 Win User

    Windows Defender Won't Turn On


    O.k....Out of curiosity I installed Avast free AV.....then decided to stay with Windows Defender, and so uninstalled Avast......now, Defender won't turn on, it tells me that "another anti virus programme" is running...... any help to turn it back on appreciated.......Del.

    :)
     
    Del 80, Sep 14, 2017
    #1
  2. JOSEPHZHAO
    JosephZhao Win User

    Windows Defender won't turn on when I try to turn it on. It says operation failed because it timed out.

    * Original Title: Windows Defender

    Windows Defender won't turn on when I try to turn it on. It says operation failed because it timed out. Is there a way to turn it on?
     
    JosephZhao, Sep 14, 2017
    #2
  3. KAT4DOGS
    kat4dogs Win User
    Message that Windows defender is turned off. I can't turn it on.

    I get a message that windows defender is turned off, but when I try to turn it back on it times out and won't turn on. What do I do?

    * Original title: windows defender
     
    kat4dogs, Sep 14, 2017
    #3
  4. TAIRIKUOKAMI
    TairikuOkami Win User

    Windows Defender Won't Turn On

    TairikuOkami, Sep 14, 2017
    #4
  5. DEL 80
    Del 80 Win User
    Thanks for that, I did try it, but to no avail......just wondering if system restore would work ?.........
     
    Del 80, Sep 14, 2017
    #5
  6. TAIRIKUOKAMI
    TairikuOkami Win User
    If you have got one prior to installing Avast, it might.

    You can also try to run this as admin:

    [Batch] Windows Defender Enable - Pastebin.com
     
    TairikuOkami, Sep 14, 2017
    #6
  7. DEL 80
    Del 80 Win User
    O.k.....Just done a system restore, back to the day before I installed Avast......Windows Defender is now back on !!......Thanks for the replies......Del.
     
    Del 80, Sep 14, 2017
    #7
  8. DEL 80
    Del 80 Win User

    Windows Defender Won't Turn On

    Just an update to this thread.......on a second laptop, I couldn't use system restore to remove Avast, as I didn't know when it was installed (not my machine).....so used the Avast uninstaller, it worked fine, within seconds of the uninstall Windows Defender had turned itself back on, and was saying that it needed to do a scan......Del.
     
    Del 80, Apr 5, 2018
    #8
Thema:

Windows Defender Won't Turn On

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