Back to the Basement Computing Page

The Basement Blog

Recent Entries
Acrobat Printing Problem
Vista - Missing Sidebar
Update Problem - XP SP3
Vista Problem-XPS M1330
Matlab Mex Problem
Vista and Telnet
Vista and ASF
FAT32 and Windows XP
Vista Annoyances - GUI
Vista - Installing
IE7 Java Crash
Win 98 Update Problem
Speeding up Windows
Outlook Reminders
Flash Update Problem
Intermittent Boot
Invisible Hard Drive
USB Drive Quirks
Outlook .pst Backup
Windows Defender Crash
XP Print Dialog Crash
Mac OS 10.4 printing
Contact Us
Flash Security Update Problem
Saturday, May 26, 2007

A recent problem with a security update for the Flash Player illustrates how things can go wrong with the Windows Automatic Updates Service. The Windows Automatic Updates Service runs within the svchost.exe process in Windows XP, as can be seen by typing the command "tasklist /svc" at the command prompt. It runs with the name "wuauserv" (see fig. 1 below).

Fig. 1 - The Automatic Update Service

Figure 1 - The Automatic Update Service.

The purpose of this service (recently renamed "Microsoft Update") is to check for critical security updates from Microsoft, and if any are available it reminds the user to install them (see fig. 2). It can also be configured to install the updates automatically via the Control Panel -> Automatic Updates. The pop-up message in the system tray is displayed by the wauclt.exe process, which is launched by the wauaserv service when a high-priority update is available.

Fig. 2 - New Updates are available

Figure 2 - New Updates are available.

The Automatic component of Microsoft Update runs on Windows 2000 or newer. It connects periodically to the Microsoft update server via the network, and queries for any available updates. The frequency of these connections/checks is unknown or poorly documented, but is initiated by the client (i.e. the user's computer) and I believe it is at least once a day. Lately, these updates have been released on the second Tuesday of each month, though sometimes they are released on other days. Only "high-priority" updates are available via the Automatic Update Service. For lower priority updates, users should periodically visit the Microsoft Update web page by running Internet Explorer and clicking on Tools -> Windows Update. (see refs. # 1 to 4).

The problem

I was recently using a laptop (running XP Pro SP2) when the Automatic Update notification (fig. 2 above) popped up. Clicking on it, followed by clicking on "Custom", brought up the dialog shown in Fig 3.

Fig. 3 - Flash Security Update

Figure 3 - Flash Security Update.

The Macromedia Flash Player (now owned by Adobe) is a small add-on for web browsers that displays animations and movies from web sites. (see ref. # 5). I found it interesting that Microsoft was releasing an update for a non-Microsoft product via the Automatic Update Service, but as Security Bulletin MS06-069 (ref. # 6) explains, the Flash Player is bundled with XP SP2 these days, which is why the patch is distributed via Microsoft Update.

I went ahead and clicked on "Install", but after a few seconds the following window appeared:

Fig. 4 - Flash Security Update Install Failed!

Figure 4 - Flash Security Update Install Failed!

Going to the MS Update web site (via IE -> Tools -> Windows Update) and trying the install again did not help, and resulted in the same failure.

To debug this problem, I looked at the file C:\WINDOWS\SoftwareDistribution\ReportingEvents.log. This is a text file which logs the Update Client activity, and sure enough, near the bottom of the log I noticed the following entry:

{26DA5716-5999-4AB2-8806-800F7AF93C93} 105 80070643 AutomaticUpdates Failure Content Install Installation Failure: Windows failed to install the following update with error 0x80070643: Security Update for Flash Player (KB923789).

Not very helpful. A web search for 0x80070643 took me to the MS KB906602 web page (ref. # 7) which advises enabling Windows Installer logging, then trying again. Enabling msi logging apparently results in a file named msi<random-digits>.log being created in the Temp folder that would hopefully contain a more detailed reason for the failure.

This seemed a bit more than I wanted to do as the first step, so I took an alternate approach which led to the solution a bit faster.

The solution

I went to the MS06-069 bulletin page (ref. # 6) and used the "Download the Update" link there and saved the update installer file (WindowsXP-KB923789-x86-ENU.exe) in a temp folder on my C: drive.

Next, I tried to install the update by double-clicking on the downloaded file, This quickly showed the real reason for the failure:

Fig. 5 - Why the update failed.

Figure 5 - Why the update failed.

Apparently the version of the Flash player on the laptop was too old for the security update.

To view the currently installed version of the Flash player, I started Internet Explorer, then Tools -> Internet Options -> Settings -> View Objects, which showed a window like the following:

Fig. 6 - Which version is currently installed.

Figure 6 - Which version is currently installed.

This shows that this laptop had version 7.0.19 of Adobe Shockwave Flash player installed.

Next I went to the Flash player download page at Adobe (Adobe web site, then click on the "Get Adobe Flash Player" link etc.) which led to the download page and the information that the new version was 9.0.45.

Clearly that was the reason for the problem, so I proceeded to click on the "Install Now" button, and installed the new version of the Flash Player. Checking the version as before in IE now showed the new version:

Fig. 7 - Version is updated.

Figure 7 - Version is updated.

Next, I went to the Windows Update web site again, and had it search for updates, and this time it did not report any pending updates. The new version of the Flash player already included the patch, and did not need the KB923789 update any more.

Problem solved.


Windows/Microsoft Update is a very useful service, and I highly recommend that everyone enable Automatic Updates to keep up with high-priority security updates. However, it is not perfect, and unexpected problems can sometimes arise. These can range from the very serious ("system crashes after applying an update"), which thankfully is not very common, to the nagging/nuisance type problem seen in today's example. One of my earlier blog entries (see bb20070323_02.asp) described an Office 2003 update which caused the Print dialog to crash.

What could Microsoft have done to avoid today's problem? Mainly, two things:

  • Do not offer an update as "available" if it does not apply to the version of the software present on that system.
  • Show clear plain-language error messages, rather than cryptic hex codes.

What should you, the user, do when you encounter problems with Windows Updates?

  • If the update installs, but causes serious problems, then you can uninstall the update while you investigate. Updates can be uninstalled via Control Panel -> Add/Remove Programs. If you don't see the updates listed there, make sure the box at the top labeled "Show Updates" is "checked". There are normally many updates, but you can use the "Installed on" information with each to narrow it down to the latest ones.
  • If the update fails to install, check both the date and time on your system. If they are off by more than a few minutes, updates will sometimes fail to install.
  • Examine the file C:\WINDOWS\SoftwareDistribution\ReportingEvents.log (with Notepad) to see if there is an explanation of why the update failed.
  • Make sure you are logged in with Administrator privileges. Most security updates require it.
  • Try the method that worked here, i.e. download the update separately from the corresponding KB article page at Microsoft, and try installing it manually.
  • Open a command window and register the following DLL's (this is particularly effective if you recently upgraded your OS)
    • regsvr32 wuapi.dll
    • regsvr32 wuaueng1.dll
    • regsvr32 wuaueng.dll
    • regsvr32 wucltui.dll
    • regsvr32 wups2.dll
    • regsvr32 wups.dll
    • regsvr32 wuweb.dll
  • Work through the troubleshooting tips at
  • Also see
  • There could be corrupted updates in the download folder. Try the following:
    • Open a command prompt window and type "net stop wuauserv" (without quotes)
    • Rename the downloads folder, e.g.
      "rename c:\windows\softwaredistribution c:\windows\badupdates"
    • Restart the update service, type "net start wuauserv"
    • Start IE and try the updates again.
  • Make sure you are using a recent version of Internet Explorer (v6.0 or later).

If you encounter a problem/solution with Microsoft Updates not covered above, do let me know how you solved it.


  1. Microsoft Update FAQ
  2. Microsoft Update
  3. Windows Update, Microsoft Update, and Automatic Updates
  4. Microsoft Update versus Windows Update...
  5. Adobe Flash Player
  6. Microsoft Security Bulletin MS06-069
  7. Troubleshoot Windows Update ... Issues
  8. You receive a "0x800A01AE" error message or a...

(in order from older to newest)

"Having the same problem but of course after going throught the technobabble of the Windows sites am glad to have one that: 1. Has the correct answer 2. I can read and understand."

Sep. 19, 2007, 12:51 AM by Vernon

"Thank you - I've spent hours trying to locate a fix for this Update "uninstallable" download (KB923789). I'll try your suggestion of installing a newer version of Flash Player."

Oct. 19, 2007, 5:18 PM by md

"Thank you very much for explaining this!

I have been stuck with this problem for a long time now, and finally it is solved thanks to you.

One really annoying thing was that every time I tried (and failed) to install this update, Windows Update seemed to forget about a number of other high-priority updates which had already been installed successfully. So I wasted a LOT of time re-installing updates due to this problem."

Jan. 23, 2009, 10:26 AM by Phil

Leave a comment
(We reserve the right to edit or delete any comment considered offensive or off-topic)


Your Name: (or just initials - this will appear on the web page)

Your e-mail address: (Optional - this will NOT appear on the web page)



Enter this text into the box below

Confirmation Code (required*) (what is this?)
(* enter the 5-digit number from the image above into the box below)


Note: Click the Submit button only once, then wait about 10 secs for a response
Do remember to enter the 5-digit confirmation code from the image, before clicking on Submit.

(This page last modified on May 6, 2009)

Back to Top
Back to The Basement Computing Page
Back to The Basement

Please send questions, complaints or comments to