Windows Defender Error 126

Hello.

I am having trouble fixing my Windows Defender and need some assistance. Every time I boot up my computer, I am prompted with this error message:

"Application failed to initialize: 0x800106ba. A problem caused Windows Defender service to stop. To start the service, restart your computer or search Help and Support on how to start the service manually."

When I go to Start -> Run -> Services.msc and try and start WinDefend I get this error message:

"Windows could not start the WinDefend service on Local Computer. Error 126: The specified module could not be found."

and when I right-click on WinDefend and go to properties, I get this error message:

"The system cannot find the file specified."

Now, all of this started after I used a program called Registry Easy to "clean" my computer. I'm assuming this messed up the Windows Defender registry keys and thus creating this problem. Now I am lost at how to fix it, the program's built in registry back-up that was created before the "cleaning" failed to restore functionality. I used this program because my computer is locking up during random times of use, which unfortunately is still happening.

I tried the steps on this page:
http://support.microsoft.com/?kbid=931849

but to no avail. Windows Defender is not listed under Programs and Features thus I cannot uninstall it. When I attempt to install Windows Defender, I am prompted with this message:

"You do not need to install this software because Windows Defender is included in Windows Vista. You can access Windows Defender from the Security section of the Windows Control Panel."

I then tried the last step on that page which was:

4. If this issue is not resolved after you complete step 3, follow this step:

1. Click Start, click Run, type regsvr32 file name, and then click OK.

Note In this step, file name is a placeholder for the following files.

Repeat this procedure for the following files:
* wuapi.dll
* wuaueng.dll
* wucltui.dll
* wups.dll
* wuweb.dll
* atl.dll
* softpub.dll
* wintrust.dll
* initpki.dll
* mssip32.dll

Almost all of them failed with error message:

"The module "FILE NAME.dll" was loaded but the call to DllRegisterServer failed with error code 0x80070005."

From other forums I looked at, I tried running "sfc /scannow" in an administrative command prompt but to no avail. It said:

"Windows Resource Protection did not find any integrity violations."

I ran a full anti-virus scan with avast! which came back with no reports.

I ran a hard-drive error check but to no avail.

My drives aren't defragmented, I use Diskeeper 2010.

I'm out of ideas from here..
Any help is greatly appreciated!
Thanks.

Hi desiderius, welcome to WhatTheTech.

Have you tried doing a System Restore to before you ran the registry cleaner?

You can prevent Windows Defender from running at boot, even if there is no clear cut way to remove it. How to disable Windows Defender from starting when Vista boots. I would also disable the Windows Defender service (Start / Run services.msc press Enter).

I created a restore point before I did the registry cleaner but for some reason, it is not being listed. The only restore points I have are from the cleaning onwards. I think this program really messed up my computer. Other programs aren't working as well such as the ASUS update tool which is BSODing with error: "SYSTEM_SERVICE_EXCEPTION" I disabled the Windows Defender from the startup via msconfig. How can I disable it in services.msc if whatever option I choose results in an error?

Can you start Services? If so, scroll down to Windows Defender and double click on it. Click Stop if it's running then set Startup to Disabled. Reboot and it should no longer be running.

Do you have your data backed up? If not, now would be a good time to do so as it's possible the only way to fix this will be with a Repair Install or a Clean Install.

You can also try a Vista Startup Repair.