BleepingComputer.com: Windows Defender Won't Start

Hi Everyone,

I recently suffered a virus infection and upon it's removal by MBAM, Windows Defender no longer works. As a result, I visited the Bleeping Computer Malware removal section and all viruses/malware were removed by Malware Response Team Member SweetTech so my laptop is free of viruses.

He referred me to the Windows Section regarding this error screen which appears each time I try to activate Windows Defender:

"Windows Defender Application failed to initialize: 0x80070006. The handle is invalid."

This computer came with Vista Home Edition. I have never disabled Windows Defender, have never upgraded the system from XP to Vista, and never changed any default settings with Defender.

Please advise as to what procedures I can take to restore Windows Defender. Any help you can provide is greatly appreciated.

Thank you and best regards,
Justin

If I were you I'd disable Defender permanently (set the Windows Defender Service to DISABLED). Defender is a complete waste of resources and is not nearly as good as MalwareBytes or Super Antispyware.

Allan, on 11 June 2011 - 02:47 PM, said:

Hi Allan and thank you for replying :D

I have both MBAM and Superantispyware. I also use Avira Antivirus as my main/active antimalware program as well as Spybot SD. The main reason I'm a bit concerned is because I normally receive Windows updates every other day (usually for Defender) and I haven't had a new installation update since May 29 so I was a bit worried.

After the virus was removed by MBAM, Defender no longer worked and I'm wondering if it was because it was deleted or the virus did something to the registry or simply turned off Defender.

Please advise.
Thank you for the help.
Justin

Sorry, there's know way for me to know why you have the problem. If that's the only issue, don't worry about it. If you notice other problems let us know.

Hi Allan,

So I guess as long as I have a real-time active antivirus program such as Avira, I shouldn't need to worry about Windows Defender being disabled.
Could you please advise if I should also install Avast or just leave Avira as my primary antivirus program?

Thank you again for the help!

You never needed Defender - it was just a bad app that MS dropped quickly. Yes, just Avira is fine - and no - DO NOT EVER have two anti virus programs installed, let alone running resident. Either Avira or Avast - your choice - but not both. And you're most welcome.

This post has been edited by Allan: 11 June 2011 - 03:49 PM