Stealth Windows update prevents XP repair

Scott dunn By Scott Dunn

A silent update that Microsoft deployed widely in July and August is preventing the “repair” feature of Windows XP from completing successfully.

Ever since the Redmond company’s recent download of new support files for Windows Update, users of XP’s repair function have been unable to install the latest 80 patches from Microsoft.

Repaired installations of XP can’t be updated

Accounts of conflicts with XP’s repair option came to our attention after Microsoft’s “silent install” of Windows Update (WU) executable files, known as version 7.0.600.381, was reported in the Sept. 13 and 20 issues of the Windows Secrets Newsletter.

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The trouble occurs when users reinstall XP’s system files using the repair capability found on genuine XP CD-ROMs. (The feature is not present on “Restore CDs.”) The repair option, which is typically employed when XP for some reason becomes unbootable, rolls many aspects of XP back to a pristine state. It wipes out many updates and patches and sets Internet Explorer back to the version that originally shipped with the operating system.

Normally, users who repair XP can easily download and install the latest patches, using the Automatic Updates control panel or navigating directly to Microsoft’s Windows Update site.

However, after using the repair option from an XP CD-ROM, Windows Update now downloads and installs the new 7.0.600.381 executable files. Some WU executables aren’t registered with the operating system, preventing Windows Update from working as intended. This, in turn, prevents Microsoft’s 80 latest patches from installing — even if the patches successfully downloaded to the PC.

I was able to reproduce and confirm the problem on a test machine. When WU tries to download the most recent patches to a “repaired” XP machine, Microsoft’s Web site simply states: “A problem on your computer is preventing the updates from being downloaded or installed.” (See Figure 1.)

Windows update errorFigure 1. After a repair install of XP, which resets the operating system to its original state, Windows Update can’t install the 80 most-recent patches from Microsoft.
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Most ordinary Windows users might never attempt a repair install, but the problem will affect many administrators who must repair Windows frequently. Anyone who runs XP’s repair function will find that isolating the cause of the failed updates is not a simple matter.

Beginning in July, it is not possible for Windows users to install updates without first receiving the 7.0.6000.381 version of nine Windows Update support files. (See my Sept. 13 story for details.) If Automatic Updates is turned on, the .381 update will be installed automatically. If AU is not turned on, you’ll be prompted to let Windows Update upgrade itself before you can installing any other updates. Consequently, users are forced to get the silent update before they can attempt to install Microsoft’s latest security patches.

The problem apparently arises because seven of the DLLs (dynamic link library files) used by WU fail to be registered with Windows. If files of the same name had previously been registered — as happened when Windows Update upgraded itself in the past — the new DLL files are registered, too, and no problem occurs. On a “repaired” copy of XP, however, no such registration has occurred, and failing to register the new DLLs costs Windows Update the ability to install any patches.

Registering DLL files is normally the role of an installer program. Unlike previous upgrades to WU, however, Microsoft has published no link to an installer or a downloadable version of 7.0.6000.381. Strangely, there’s no Knowledge Base article at all explaining the new version. The lack of a KB article (and the links that usually appear therein) makes it impossible for admins to run an installer to see if it would correct the registration problem.

One possible fix is to install an older version of the Windows Update files (downloadable from Step 2 of Microsoft Knowledge Base article 927891) over the newer version. This involves launching the installer from a command line using a switch known as /wuforce.

That corrects the registration problem, although even in this case you must still accept the .381 stealth update (again) before you can get any updates. The fact that the /wuforce procedure solves the problem suggests that the installer for .381 is the source of the bug.

Manually registering files solves the problem

If you find that Windows Update refuses to install most patches, you can register its missing DLLs yourself. This can be accomplished by manually entering seven commands (shown in Step 2, below) at a command prompt. If you need to run the fix on multiple machines, it’s easiest to use a batch file, as Steps 1 through 5 explain:

Step 1. Open Notepad (or any text editor).

Step 2. Copy and paste the following command lines into the Notepad window (the /s switch runs the commands silently, freeing you from having to press Enter after each line):

regsvr32 /s wuapi.dll
regsvr32 /s wuaueng1.dll
regsvr32 /s wuaueng.dll
regsvr32 /s wucltui.dll
regsvr32 /s wups2.dll
regsvr32 /s wups.dll
regsvr32 /s wuweb.dll


Step 3. Save the file to your desktop, using a .bat or .cmd extension.

Step 4. Double-click the icon of the .bat or .cmd file.

Step 5. A command window will open, run the commands, and then close.

The next time you visit the Windows Update site, you should not have any problem installing the latest patches.

In my articles in the last two weeks on the silent installation of the Windows Update support files, I stated that the stealthy upgrade seemed harmless. Now that we know that version .381 prevents a repaired instance of XP from getting critical patches, “harmless” no longer describes the situation. The crippling of Windows Update illustrates why many computer professionals demand to review updates for software conflicts before widely installing upgrades.

“I understand the need to update the infrastructure for Windows Update,” says Gordon Pegue, systems administrator for Chavez Grieves Engineers, a structural engineering firm in Albuquerque, N.M. “But I think Microsoft dropped the ball a little bit communicating how the system works. Administrators should know these sorts of things, in case problems arise.”

A Microsoft spokeswoman offered to provide an official response about the situation, but I received no reply by press time.

If you ever need to run the repair option on XP, first see the detailed description provided by the Michael Stevens Tech Web site.

I’d like to thank Windows Secrets contributing editor Susan Bradley for her help in bringing reports of this problem to light.

Have a tip about Windows? Readers receive a gift certificate for a book, CD, or DVD of their choice for sending tips we print. Send us your comments via the Windows Secrets contact page.

Scott Dunn is associate editor of the Windows Secrets Newsletter. He has been a contributing editor of PC World since 1992 and currently writes for the magazine’s Here’s How section.
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