Symptoms
Assume that you have client computers that are running Windows 8 or Windows Server 2012 in a network environment. Periodically, the online Windows Update, Microsoft Update, and Windows Store services are upgraded to new versions. However, during these migrations, client computers may switch back and forth repeatedly between the old service version and the new service version unexpectedly. Additionally, this behavior causes poor performance of client computers, and disrupts the regular schedule of Automatic Updates.
Note The expected behavior is that each client computer switches one time from the old service version to the new service version.
Cause
This issue occurs because of an issue in the Windows Update Agent software. Therefore, the client computer discards the previously cached configuration files, and uses the newly downloaded configuration files regardless of whether the downloaded configuration files are more recent than the previously cached configuration files.
When a client computer connects to the Windows Update, Microsoft Update, or Windows Store service, the Windows Update Agent software runs on the client computer to receive configuration files that indicate which version of the service the client computer should use. The configuration files are cached locally for later use. During the service migration, the client computer may randomly receive configuration files that refer to either the old version of the service or the new version of the service. This mechanism makes sure that the client computer only uses the newly downloaded configuration files if they are more recent than the previously cached configuration files.
However, because of an issue that occurs in the Windows Update Agent software, the client computer always uses the newly downloaded configuration files, regardless of whether the newly downloaded configuration files are more recent than the cached configuration files. Therefore, the client computer randomly switches back and forth between service versions, depending on which configuration files are most recently received.
Resolution
Update information
To resolve this issue, install update rollup 2889784. For more information about how to obtain this update rollup package, click the following article number to view the article in the Microsoft Knowledge Base:
2889784 Windows RT, Windows 8, and Windows Server 2012 update rollup: November 2013
Status
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
More Information
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates
