When I try to do anything with Windows Defender, I get a dialog box saying "The application failed to initialize: 8x80070006. The download handle isinvalid." I have tried to download and reinstall WD, but always receive the message stating that WED is already a part of the security suite. How can I repair or reinstall WD so that I can use it?

What "security suite" do you have installed?Carey Frisch

When I try to do anything with Windows Defender, I get a dialog box saying "The application failed to initialize: 8x80070006. The download handle isinvalid." I have tried to download and reinstall WD, but always receive the message stating that WED is already a part of the security suite. How can I repair or reinstall WD so that I can use it? Windows Defender is part of your operating system. It cannot be uninstalled or re-installed. Windows Defender will be shut down if you have one of the following security programs installed : MSE - Microsoft Security Essentials AVG McAfee Norton Those programs have their own defenders. Running 2 defenders in the same machine will create conflicts. That is why they will turn off WD. Tell us what " anything " you want to do with Windows Defender. Maybe there is another way.If it solves your problem, I did it. If it does not, my twin brother did it.

Hi Davidhk129, you said.. Windows Defender will be shut down if you have one of the following security programs installed : MSE - Microsoft Security Essentials AVG McAfee Norton In fact here I have MSE(defender) running quite happily with Mcafee Security Centre and also Iobit Malware fighter. And any one of them could prompt me during real time scanning of files. And all three can be triggered to start a virusScan on the drive. Though I've NOT tried to deliberately Scan with ALL 3 at once as likely the disk/CPU would stall.. Yeah sure they might complain initially - but if you're determined it IS possible! pkn2011

Hi Davidhk129, you said.. Windows Defender will be shut down if you have one of the following security programs installed : MSE - Microsoft Security Essentials AVG McAfee Norton In fact here I have MSE(defender) running quite happily with Mcafee Security Centre and also Iobit Malware fighter. And any one of them could prompt me during real time scanning of files. And all three can be triggered to start a virusScan on the drive. Though I've NOT tried to deliberately Scan with ALL 3 at once as likely the disk/CPU would stall.. Yeah sure they might complain initially - but if you're determined it IS possible! pkn2011 The only person I have interest in replying to is the OP. You are not it. You have issue with my answer, bring it to the Moderator, in this case Magon Liu.If it solves your problem, I did it. If it does not, my twin brother did it.

when I said, Yeah sure they might complain initially - but if you're determined it IS possible! Just for the record. And for informational purposes: As snapped from my startup file, (and hopefully not instigating any re-occurrence of further sour grapes by any other participant(s) herein) I post the following: Vista 32bit Business. 4gb DDR2 @2Ghz dual cpu. -------booted tasks (among others) Yes HKLM:Run Windows Defender %ProgramFiles%\Windows Defender\MSASCui.exe -hide Yes HKLM:Run mcui_exe "C:\Program Files\McAfee.com\Agent\mcagent.exe" /runkey Yes HKLM:Run IObit Malware Fighter "C:\Program Files\IObit\IObit Malware Fighter\IMF.exe" /autostart ------- pkn2011

In Addition: As extracted from a message posted by me in Vista Applications re: starting Defender.. ---------------------- Check processes running from task Manager for the file MSASCui.exe (defender Interface) on the path "C:\Program Files\Windows Defender\MSASCui.exe" If it's running go to that path and create a shortcut for defender from it.. If it's NOT running - go to the same path and both create shortcut and also Run the shortcut/or the MSASCui.exe ---------------------- And Further as found in same thread in Vista Applications: ie. 'Fixing "0x800106ba" Vista Windows Defender' Go into services to check that Defender Service "WinDefend" is set to Automatic. If it isn't - trying to run defender when defender is already running will cause the abovementioned error. Regards, pkn2011

How did you turn on Defender with MSE running? I have Vista Ultimate 64bit and have now installed MSE. While I like it I want Defender back for nerdy reasons. I also like to run quick scans regularly along with dinking in my registry and startup files from there. I really don't want to run AVG as its slow and lanky on my machine. So tell me how to get WD running agan on my PC. It runs both fine on XP but not Vista. Runs swmmingly with Kaspersky but my subscription bit the bullet and I can't afford another 65 clams for Kaspersky subscription again.

Hi you said.. "How did you turn on Defender with MSE running?" If you do install MSE on vista it'll take over the front end from Defender, Like it does on the Win7. Although it's there as a background process on call for MSE (and if you really want to you CAN get it running. I proved that one day here in fact - even updated Defender with MSE running) but what David said in regard to MSE and Defender is basically correct. The following is what I determined at the time. (Never posted) In regard to doing similarly on Win7 64bit - It IS possible to run the well hidden amd64 version of Defender as I have detailed for Vista in previous messages - together with Mcui & imf and also msseces.exe surprisingly. You can even update Defender thru its interface (if you first disable Windows Update). BUT - to allow MSASCui.exe to maintain control of the WinDefend service you'd really need to remove msseces.exe from bootup, which likely isn't a very forward thinking idea.. -- So only one or the other can control the "WinDefend" service at any one time. Regards, pknIf my post was helpful - give it a Vote. If it helps solve your problem - propose it as Answer. ;-)