Windows XP: Some Updates Were Not Installed

I had experienced occasional problems when trying to install updates to Windows XP SP3.  At some point, those problems stopped being resolved and started accumulating.  At the time of writing this post, I faced a situation in which the Microsoft Update webpage told me that I had 47 "High Priority" updates to install, along with seven optional hardware and software updates; and yet, each time I tried to install those updates, I got the messages "Some updates were not installed" and "The following updates were not installed."  I was concerned that these updates might be important for system security and stability.

On this particular day, I had once again sought out advice.  The summary of the steps I took, all of which failed, is as follows:

*   *   *   *   *

*** FIRST TRY ***


6. Make a folder "C:\WUAGENT" (any location/name can be used). Download into it:
   - http://download.windowsupdate.com/v7/windowsupdate/redist/standalone/WindowsUpdateAgent30-x86.exe
   - better yet, read "http://support.microsoft.com/kb/949104" and get the proper file there.
7. Start -> Run "C:\WUAGENT\WindowsUpdateAgent30-x86.exe /wuforce".
   - note: this failed for me if the "Automatic Updates" service was stopped.
   - I (RW) had to run it twice to get it to work.
8. In IE run "Tools -> Windows Updates" - perhaps a few times as it rebuilds update stuff.

*** SECOND TRY ***

First, do this:

1. Start -> Run "services.msc" (in Vista, it's Start->All Programs->Accessories->Run)
2. Right "Automatic Updates" and select "stop".
3. Start -> Run "%systemroot%"
4. Delete "SoftwareDistribution" folder and "WindowsUpdate.log"
5. Back in services, right-click "Automatic Updates" and select "start".

Then run steps 6-8, above.

*** THIRD TRY ***

Start > Run > regsvr32 wups2.dll
Then try running Windows Updates.

*** FOURTH TRY ***

REGSVR32 WUAPI.DLL
REGSVR32 WUAUENG.DLL
REGSVR32 WUAUENG1.DLL
REGSVR32 ATL.DLL
REGSVR32 WUCLTUI.DLL
REGSVR32 WUPS.DLL
REGSVR32 WUPS2.DLL
REGSVR32 WUWEB.DLL

*** FIFTH TRY ***

net stop wuauserv
regsvr32 %windir%\system32\wups2.dll
net start wuauserv

*** SIXTH TRY ***

Look at the log file for one of the updates.  Example:
Security Update for Windows XP (KB979309)

Then put that number into the following command:

%windir%\KB979309.log

In my case, the end of this log file gave me this information:
1,297: [PatchFilesFromResponseBlob] returning STATUS_READY_TO_INSTALL
1,313: KB979309 installation did not complete.
1,313: Update.exe extended error code = 0xf201

For guidance on whether the update was installed or not, see:
http://support.microsoft.com/kb/910339/. 

Following the advice on that webpage, look up that error code.  See:
http://support.microsoft.com/kb/906602/.

That didn't work for me, possibly because I had already obliterated the evidence in previous steps.