Update Failed to connect to server KB928365 80070643

I get this:

System event:
Source Windows Update Agent
Event ID 20
Installation Failure: Windows failed to install the following update with
error 0x80070643: Security Update for Microsoft .NET Framework, Version 2.0
(KB928365).
The Data are:
"Win32HResult=0x80070643 UpdateID={28190A6C-BDE4-4B91-83BC-1F0231B694B2}
RevisionNumber=101 . "

System event:
Source: DCOM
Event ID: 10010
"The server {000C101C-0000-0000-C000-000000000046} did not register with
DCOM within the required timeout."

Application event:
Source: MsiInstaller
Event ID 1015
"Failed to connect to server. Error: 0x80080005"

HKCR\Clsid\000C101C-0000-0000-C000-000000000046\ (Default) has "MSI install
Server".
Subfolder ProgID contains "(Default) IMsiServer".

WindowsUpdate.log contains
2007-08-17 10:15:56:578 1288 10b0 Report REPORT EVENT:
{6B9BD3B5-D292-4051-B103-6EEB815636C7} 2007-08-17 10:15:51:578-0400 1
182 101 {28190A6C-BDE4-4B91-83BC-1F0231B694B2} 101 80070643
AutomaticUpdates Failure Content Install Installation Failure: Windows
failed to install the following update with error 0x80070643: Security Update
for Microsoft .NET Framework, Version 2.0 (KB928365).

I cannot find a file named IMsiServer.
The Office Support Engine (OSE) service is running.
Windows XP SP2.

Any insights?

Unified .NET Framework Troubleshooting Guide
http://blogs.msdn.com/astebner/articles/454956.aspx

Use the .NET Framework setup verification tool to check for errors
If errors are found in the installed .NET Framework, then see:

What to do if other .NET Framework setup troubleshooting steps do not help
http://blogs.msdn.com/astebner/archi...11/479928.aspx

FWIW, error code 0x80070643 is just a generic error,
ERROR_INSTALL_FAILURE, with no signficance by itself other than to
indicate that an update failed to install.

As to the MSI error:
Troubleshooting a Windows Installer Issue
http://blogs.technet.com/askperf/arc...ler-issue.aspx

Start with Aaron's blog as it is *THE* source for .NET Framework/update
installation issues.

It worked.

The instructions in
http://blogs.technet.com/askperf/arc...ler-issue.aspx
pointed me to procmon.exe, which noted ACCESS DENIED on the Registry for
msiexec.exe. When I set SYSTEM permission to Full in HKCR/Installer, it
didn't work. Trying again produced an ACCESS DENIED on HKCR/. When I set
HKCR/, it worked.

It's unnerving having to fool with system control bits at this level.

It's a wonder that this stuff works at all. procmon managed to produce 13
SUCCESS events, then it started battling with INVALID DEVICE REQUEST, NAME
NOT FOUND, BUFFER OVERFLOW, INVALID PARAMETER, CANNOT DELETE, and others.
Out of 68389 events, 4506 were not SUCCESS.

(After finishing the installation, a window popped up telling me an update
was available. It's the same update I just installed! Where does it end?)

I found this article looking for a fix to my problem. I'm having a similar one, but not exactly the same. The Event Viewer shows:

Application event:
Source: MsiInstaller
Event ID: 1015
"Failed to connect to server. Error: 0x80080005"

I tried Process Monitor, took a quick look at the log but didn't find any Access Denied error, but others such as Name Not Found and the ones angbob mentioned. So my problem hasn't got anything to do with permissions.

Here's the log in case somebody wants to give me a hand (file attached).

I opened a thread on another forum, there you can find details of the issue. I know this isn't the proper forum considering my OS (Windows 7 x64), but I'm really in desperate need of help.

Any suggestion appreciated. Thanks in advance.

Edit: I suspect it might have something to do with a corrupt .NET Framework, tried the Setup Verifier from Aaron Stebner's blog (which identified errors with 2.0, 3.0 and 3.5 versions), then did a Cleanup with his utility and tried reinstalling through the Windows Components menu (.NET Framework 3.5 is inbuilt Windows 7). But that not did the trick. The verifier utility still shows errors though, but I don't know what else to try in order to repair it.