Hi Nevet. You might try this. Go to the main Windows Update window and
click on "Installed Updates" (on the left-hand side of the window, at the
bottom), and then remove "Update for Microsoft Windows (KB931099)" (only).
Reboot. Reboot again. Go back to Windows Update, and re-install the same
update, by clicking on the Check for Updates button.

This should essentially re-install Windows Defender on Vista.


"Nevet" <Nevet@discussions.microsoft.com> wrote in message
news:41903B05-21DC-479F-8C51-2250FE3BDF06@microsoft.com...
> Thanks, Engel! This looked right, but doesn’t seem to apply to Vista.
> Running appwiz.cpl, Windows Defender doesn't even show up on the list of
> installed Program and Features, nor under Windows features to turn on or
> off.
> It is also not listed in the Windows Installer CleanUp utility
> (http://support.microsoft.com/kb/290301/). And when I try to reinstall
> from
> http://www.microsoft.com/athome/secu...yware/software, as the KB
> article
> instructs, I get the 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.”
>
> Windows Security Center shows (under “Malware protection”) that Windows
> Defender is turned off. “Turn on now” churns for a while, then says,
> “Security Center can’t turn on Windows Defender. Please try again
> later.”
>
> Any other ideas?
>
>
> "Engel" wrote:
>
>> Hello Nevet,
>>
>> Error message when you run Windows Defender: "Error Code 0x800106ba
>>
>> Try this
>> http://support.microsoft.com/?kbid=931849
>>
>>
>> I hope this post is helpful.
>>
>> Let us know how it works ºut.
>>
>> --
>>
>>
>>
>> "Nevet" wrote:
>>
>> > Running Vista Home Premium. When starting the OS, I get an error
>> > message
>> > from Windows Defender:
>> >
>> > "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."
>> >
>> > Attempting to manually start the service brought up another error:
>> >
>> > "Windows could not start the Windows Defender service on Local
>> > Computer.
>> > Error 0x80092003: An error occurred while reading or writing to a
>> > file."
>> >
>> > I have uninstalled my third-party (McAfee) security suite so Defender
>> > is all
>> > I have on this machine.
>> >
>> > I found similar reports on various newsgroups but no solution,
>> > workaround or
>> > fix offered.
>> >
>> > Any suggestions?
>> >
>> > --Nevet