Hi Mr. Patrick:
I don't think your update problem is with Vista. I found this info in a
windows update forum:
"Microsoft struggles with Patch Tuesday
By Ina Fried
Staff Writer, CNET News.com
Published: October 10, 2006, 12:12 PM PDT

Microsoft on Tuesday released a slew of patches for Windows and Office, but
a glitch prevented the company from pushing the updates out automatically.

The patches, which include critical fixes for both Office and Windows, can
be manually downloaded from Microsoft's Web site, and the company said it
hopes the more-automated tools will have the patch available later on
Tuesday. Microsoft said that its technical teams "have been working around
the clock" to fix the updating problems.

"Due to technical difficulties experienced on the Microsoft Update platform,
security updates released today are not currently available via Microsoft
Update, Automatic Updates, Windows Server Update Services or Windows Update
v6," the software maker said.

More here...

[url]http://news.com.com/Microsoft+strugg...tag=html.alert[/url]

Hope this helps"

I also had problems downloading updates for one of my 2 xp computers that
day. The update worked fine on my month old system but got the same error
message you did for the 1 yr old XP system. A day later the updates
downloaded and installed fine if you haven't already found out.

xiowan.........in tucson

"Schevenels Patrick" wrote:
[color=blue]
> Hello.
>
> I have a problem with Windows Update under Windows Vista Build 5728 :
> Windows could not search for new updates
> Errors found :
> Code 8024400A
>
> On internet bulletin boards, some people tell that it's due to an update of
> Windows Defender but no one knows how to solve the problem.
>
> Do you have an idea ?
>
> P.S. : Microsoft Update is activated
>
> Thanks
> Patrick Schevenels
>
>
>[/color]