After applying the requiced registry hack (registry hack to apply Vista SP1 v113) to enable Windows Update and/or Microsoft Update into system registry, some computers which has already installed Windows Vista SP1 still does not been targeted for Vista SP2 beta delivery in WU or MU.

In other words, users unable or cannot get to see Windows Vista SP2 as an update listed on Windows Update, even thought the required registry key has been merged and added to the registry, and despite users keep refreshing the Windows Update in currently supported Windows Vista SP2 beta languages, such as English (both x86 32-bit and x64 64-bit is supported), with complete Vista SP1 already installed.

The problem that cause failed detection of Vista SP2 beta target validity to delivery the SP2 beta update by Windows Update is most likely caused by wrong, or rather old version of Windows Update Agent (WUA). Windows Update Agent manages updates that will be installed on your computer, and is used by Windows Update Web site to provide the latest updates to all Windows operating system. The Windows Update Agent also works together with servers that are running Microsoft System Management Server and Windows Server Update Services (WSUS) in a corporate environment.

By right, Windows Vista SP1 should have Windows Update Agent version 7.2.6001.784 or higher (note: user can check the version of Windows Update Agent by checking version information of files such as Wups.dll, Wuweb.dll, Wuauclt.exe, Wuapi.dll and Cdm.dll). By default, before update, Windows Vista SP1 has only Windows Update Agent with build version 7.0.6001.18000. Only WUA version 7.2.6001.784 or higher can upgrade to Windows Vista SP2 beta versions in Windows Update.

To update the Windows Update Agent, KB949104 provides the required download link to the version 7.2.6001.788 of Windows Update Agent. The direct download links for the setup download links are also listed below.

For an x86-based computer: windowsupdateagent30-x86.exe package

For an x64-based computer: windowsupdateagent30-x64.exe package

For an Itanium-based computer: windowsupdateagent30-ia64.exe package

Note that Windows Vista Business edition is reported to be must install the latest version of Windows Update Agent in order to get to see Windows Vista SP2 beta been offered in WU after applying the registry hack.