On each logon following installation of the Desktop Experience feature (which includes Windows Defender), the following error message appears: "Application failed to initialize: 0x800106ba . a problem caused Windows Defender Service to stop. To start the service restart the computer or search help and Support on how to start a service manually. " Attempting to start the Windows Defender service manually generates the following error: "Windows could not start the Windows Defender service on Local Computer. Error 0x80092003: an error occurred while reading or writing to a file." Using Process Monitor, I looked for indications of read or write failures, but I couldn't find anything definitive. Is there any way of getting the Windows Defender service to start?

I experienced today also a problem with Windows Defenderthis may be related:Windows Defender service terminated unexpectedly, error: 0x80010005 Erkan YILMAZ

Solved: this happens if the %ProgramData% environmental variable is set to a path other than the default (C:\ProgramData). In my case, the path was D:\ProgramData. A closer look and Process Monitor output showed several PATH NOT Found lines. Even when ProgramData is specified to be on D: in an answer file, Windows Defender installs its files into C:\Program Data. For now, the workaround is to stick with the default location of ProgramData or to copy the files that Windows Defender installs to D:\ProgramData\Microsoft\Windows Defender.

I have the same issue, but have not changed the Program data location. Any ideas?

I have the same problem Application failed to initialize: 0x80010005 The machine is a Compaq Presario straight out of the box less than a week old and no major changes.

Your error code (0x80010005) is different than mine. My error code (0x80092003) was caused by inability to find the ProgramData folder when it was in a non-default location. Yours might be RPC-related. You could check if you have any other RPC-related error or warning events in your System or Application logs. Did you add the Desktop Experience feature before you tried to run Windows Defender?I just verified that Windows Defender starts and runs on a PowerEdge 2900 runnning WS08 RC0 x64 Standard. I did this after installing the OS and adding the Desktop Experience feature, but before adding any other roles, role services, or features.

Thank you for writting thsi fix but I still dont understand how to fix it. Could you maybe describe to me how exactly how to fix it. Thank you.

This is not an adequate solution at all! Workaround? What on earth are you talking about? HOW do you get the program to start when there have been no alterations to the location of the original ProgramData files? Just simple plain english of how to do this if you don't mind. I'm running windows Vista.

Hi. All I just found a solution for: "Application failed to initialize: 0x800106ba . a problem caused Windows Defender Service to stop. To start the service restart the computer or search help and Support on how to start a service manually. " and "Windows could not start the Windows Defender service on Local Computer. Error 0x80092003: an error occurred while reading or writing to a file." overwrite C:\ProgramData\Microsoft\Windows Defender\ with http://www.megaupload.com/?d=BTS3TCV0 sorry my bad english

Okay, try this: I have been searching for the solution for hours. Then I started experimenting. I finally came up with this solution: When you get the dialog box asking if you want to retry or cancel, leave it alone. Next navigate to the location where Window Defender is installed. Mine is C:\Program Files\Windows Defender. Next click on the MSASCui.exe icon. The Windows Defender Program will open. Next go back to the installation dialog then click on retry. The installation will finish then Windows Defender will start looking for updates. Easy peasy, lemon squeezie.