The automatic security download from Microsoft has tried several times to 
download Microsoft .NET Framework 1.1 SP1 Security Update for Win2000 and 
WinXP KB979906 and the installation has failed.  Error code is O or 0x643.

I am using WinXP Home Edition, Ver 5.1 and SP3.  No help from MX on-line 
do-it-yourself stuff.  Not sure what to do next.  Any help or suggestions?
-- 
Pink Lady

[Crosspost to Windows Update newsgroup]

OPTION A: See the "How to obtain help" section of 
http://support.microsoft.com/kb/979906

For home users, no-charge support is available by calling 1-866-PCSAFETY 
(1-866-727-2338; and/or 1-866-234-6020 and/or 1-800-936-5700) in the United 
States and in Canada or by contacting your local Microsoft subsidiary. 
There is no-charge for support calls that are associated with security 
updates.  When you call, clearly state that your problem is related to a 
Security Update and cite the update's KB number (e.g., KB979906).

Or you can...

Start a free Windows Update support incident email request:
https://support.microsoft.com/oas/default.aspx?gprid=6527

Customers who experience issues installing Microsoft security updates also 
can visit the following page for assistance: 
https://consumersecuritysupport.microsoft.com/

For more information about how to contact your local Microsoft subsidiary 
for security update support issues, visit the International Support Web 
site: http://support.microsoft.com/common/international.aspx

For enterprise customers, support for security updates is available through 
your usual support contacts.

==================================

OPTION B: First run the Fix It in this KB article & see if the update will 
install after doing so:

How to fix MSI software update registration corruption issues
http://support.microsoft.com/kb/971187

If no joy, see...

When installing updates using Windows update or Microsoft Update you may 
receive Error 0x643 or 0x80070643 (23 Oct-09)
http://support.microsoft.com/kb/976982

Then proceed per the following:

~~~~~~~~~~~~~~~~~~~~~~~~

Step #1 => Before doing anything else, write down what .NET Framework 
versions are currently installed:

    How to determine which versions of the .NET Framework are installed and 
whether service packs have been applied
    http://support.microsoft.com/kb/318785

Step #2 => Now see Resolution Method 2 in this related KB article: 
http://support.microsoft.com/kb/923100

After running the .NET Framework Cleanup Tool (not the Windows Installer 
Cleanup utility!), reinstall all .NET Framework versions (but only the ones 
you wrote down in #1 above) manually using the download links on the page 
then run Windows Update manually to install security updates for same.

Download links for .NET Framework Cleanup Tool:

• 
http://cid-27e6a35d1a492af7.skydrive.live.com/self.aspx/Blog_Tools/dotnetfx_cleanup_tool.zip

• 
http://blogs.msdn.com/cfs-file.ashx/__key/CommunityServer-Components-PostAttachments/00-08-90-44-93/dotnetfx_5F00_cleanup_5F00_tool.zip

NB: If you remove .NET Framework 3.5 (SP1) using the tool, reinstalling .NET 
Framework 3.5 will also install .Net Framework 2.0 SP2 and 3.0 SP2; then 
Windows Update will offer .NET Framework 3.5 SP1.

IMPORTANT! => If you remove .NET Framework 3.5 (SP1), reinstall your .NET 
Framework versions in the following order:

    1. .Net Framework 3.5, then...
    2. .Net Framework 1.1, then...
    3. .Net Framework 1.1 SP1

NB: KB923100 references this page: 
http://blogs.msdn.com/astebner/archive/2006/05/30/611355.aspx.  Please read 
ALL of it as well as the related page 
http://blogs.msdn.com/astebner/pages/8904493.aspx before using the .NET 
Framework Cleanup Tool.

Step #3 => Check-in at Windows Update and install any critical security 
updates offered.
-- 
~Robear Dyer (PA Bear)
MS MVP-IE, Mail, Security, Windows Client - since 2002


CK wrote:
> The automatic security download from Microsoft has tried several times to
> download Microsoft .NET Framework 1.1 SP1 Security Update for Win2000 and
> WinXP KB979906 and the installation has failed.  Error code is O or 0x643.
>
> I am using WinXP Home Edition, Ver 5.1 and SP3.  No help from MX on-line
> do-it-yourself stuff.  Not sure what to do next.  Any help or suggestions?