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.