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

Locked Question. This question was migrated from the Microsoft Support Community. You can vote on whether it's helpful, but you can't add comments or replies or follow the question.

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  1. Anonymous
    2015-08-29T17:48:58+00:00

    Funny you all manage to reply and state your own problems because any time I do that there is always some guy who comes to tell me to go to my own page and to comment there but that way there is no dialogue? By dialoguing maybe we manage to help each others? No idea why he resents me getting in contact with people as we all have the very same problema!

    Anyway, I tried a few things but nothing worked as instead of the Defender I get a blank document so I have given up and paid for Avast which is working fine but I prefer to have a free anti-virus. Some of the solutions offered here, maybe very eficiente but were too complicated for me. What I don't understand is why so many people have the same problem.... it seems to me that there is some conceptual problem with the Defender!

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  2. Anonymous
    2015-08-29T18:10:34+00:00

    I removed all anti malware programs like Malwarebytes and Spybot, then went into the run dialog

    box and typed hh http://live.sysinternals.com and removed all pink lined items, rebooted, and voila....Defender was on!

    I can always reinstall Malwarebytes, Spybot, etc.

    You can always chat by chat box messages with the Microsoft help desk.  They told me if it was a simple fix, the service is free.  If it's a difficult fix, you pay for a service call.

    https://support.microsoft.com/en-us/contact/chat/4/

    Another option is Costco.  Their free Concierge tech support is always free if you bought your computer there but many times they will help even if you did not buy it there.   1-866-861-0450

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  3. Anonymous
    2015-08-30T15:56:28+00:00

    I'm getting a 577 error when I try to start Windows Defender ... my pc came pre-loaded with McAfee.  Do I need to uninstall that first?

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  4. Anonymous
    2015-09-01T23:27:58+00:00

    I had this problem and some others too such as "DFS.SystrayUI has stopped working" and "IAStorlcon has stopped working" and "Dell Backup and Recovery Toaster has stopped working". I have a Dell Inspiron running Windows 8.1. I cannot remember where it was recommended but I downloaded the program "Reimage Repair" it did its free scan, I paid for the fix it program and now all the errors have disappeared and the computer no longer takes 5 minutes to boot up!

    Frankly the program was worth the money. One minor issue. On first pass through it seemed to stall at about 80% completed so I left it overnight and in the morning the screen was blank. I thought "Oh No!". I could not wake it up so I reset. After the usual warnings about how the OS had not been shut down properly, I rebooted and the Reimage Repair program gave message that all was repaired!. I ran the analysis again and then also the fixit, and then it completed normally. After reboot the computer is now back to how it should be. Thoroughly recommend the program.

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