Windows Defender update FAIL



When I try to install the Windows Defender update, it continuesly fails.
I tried to install throuw Windows Update. It said that the update could no
be installed.
When i used Windows Defender to update it says:
Error found: Code 0x80070643

I reinstalled Windows Defender, but it didnt work..
I cleared the Software Distribution > Download folder and tried but it still
failed.. I have searched the newsgroups and google for a few days with no

This is pissing me off. I have reinstalled Windows again probably 3-4 times
THIS YEAR.. I dont want to do it again.

By the way, i have 2 harddisks. Both have XP and the exact same programs. On
one Defender works - on the other it dosent.

My Windows Update log can be found in:

* start looking from 2007-03-27 (the first erros are there)
Thanks for your replies :)


Hello Legace,

Download Ccleaner and Dial-aFix

Ccleaner -
Note, uncheck Yahoos toolbar during install.

Do the scans with all the check marks on.
Open Ccleaner and press "Windows" "Aplications" and "Run Cleaner" from the
menu choose 'Issues' and then press scan for issues, Repair any fºund.

Better if is run in safe mode.

Run the above clenaer in safe mode. Ccleaner with all 3
settings(windows,apps &
issues) and clear anything found, reboot and see if Windows Defender update.


CCleaner even has a built-in Registry Cleaner. It's not the best (not
CCleaner's main function), but it will find invaild registry entries that
most Registry Cleaners will not. Unlike the Disk Cleaners with a Registry
Cleaner, CCleaner does really fast scanning for Registry Issues. The reason
is CCleaner doesn't want to effect Windows performance or effect any
applications. It's better to be safe than sorry!

The first time you run CCleaner's Issues scanner you'll have to keep running
it back-to-back until it finds nothing. One scenario is a registry key may
only be a reference pointing to a completely different location in the
registry and when it's removed then that reference link is also noticed as
being invalid on a subsequent scan. It's generally a good idea to keep
running the Issues scan until nothing is listed.

There is also a third-party fix which has had good results for a number of
folks here:
Dial-a- Fix

Run this program with all the functions activated in safe mode.

Scroll down about 2/3 of the way to Download Dial-a-fix

Dial-a-fix is essentially a scripted run through of the standard Microsoft
fixes, I believe. I think I've only seen one failure when we've referred
people to it. I'm not too enamoured of some of the authors opinions, but
this has been a useful tool.

For the benefit of the community reading this post, please rate the pºst.
I hope this post is helpful.
Let us know how it works ºut.


I tried the CCleaner and Dial a fix - with no success.. When i tried to
update, the following message came:

The following updates could not be installed:
Definition Update for Windows Defender - KB915597 (Definition 1.17.2437.5)

Maybe its time to reinstall again.. Thanks for your help :)


Hi Legace

You can repair Windows Defender.
First exit WD, click the down arrow to the right of the white question mark
in blue circle and then click Exit Windows Defender; using Add or Remove
Programs in Control Panel. Click WD and click Change. Click Next, and then
click Updªte.

If you still have the same message, try this:
First exit WD, click the down arrow to the right of the white question mark
in blue circle and then click Exit Windows Defender; using Add or Remove
Programs in Control Panel. Click WD and click Support Information and click

Let us know how it works ºut



I solved this problem by deleting the KB925902 update. I have a ShellPack
(it edits the shell32.dll to make better icons), and this has not caused any
problem until that update. It seems that the KB925902 has some problem with
the new shell32 and does not allow Defender to update.

I hope this update you guys (I refer to Microsoft) made was not really to
make the use of shellpacks harder. This update has also affected other
programs (like Nero and F-Secure...)

I also hope that you will also fix this bug.


Hi Legace,

Windows Defender team read this forums.

Your report help them to improve the product, and to report to the proper
departaments, thanks again for your feed back.

Have a good day


Bill Sanderson MVP

Hmm - removing a patch which prevents exploitation of a security failure
that allows for remote code execution is not my idea of an improvement in
your system.

I can assure you that the patch was not made with the intent to harm the
business of any of the vendors involved. In fact, Microsoft has made a
hotfix available, and distributed it via AutoUpdate, I believe--specifically
to fix some issues relating to other vendors code and this patch.

Is it really the policy of the vendors of the ShellPack that you need to
maintain your system in a vulnerable state in order to use their product? I
suspect not. I'd encourage you to keep looking at this issue--and
watching for fixes from the third-party vendors involved. The sound card
driver which was among the first reported incompatibility has been revised
to eliminate the issue--I suspect that the other vendors involved will
manage this, too.


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