This section contains recommended best practices for creating and managing software updates to help administrators avoid common problems.

Software Update Supersedence

Software update supersedence occurs when a software update that is sent to a client computer is older than the update already on the computer. To ensure that the client computer always has the most recent version of the update and that it is never downgraded to an older version, create Applicability rules for the software update that makes the update applicable only to computers that have an older version of the software update. The following two examples show how a simple Applicability rule can be created to check for newer versions of the file, and if the result is False, the update is not installed on the computer. For the examples, assume that MyFile.exe needs to be updated to version with a creation date and time of 05/01/06 12:01:29.

Example 1

Rule Type: File Version


Path: \MyFolder\Myfile.exe

Comparison: Less Than


Example 2

Rule Type: File Creation Date


Path: \MyFolder\Myfile.exe

Comparison: Less Than

Created Date: 2006/05/01 12:01:29

Software Update Supersedence Information in Titles

When there are related software updates with varying versions, it is recommended that each software update is created by keeping the following conditions in mind:

  • The software update titles are created so they can be grouped together in the Updates Publisher.

  • It can be easily determined which software updates refer to superseding versions of the same update.

Note that these recommendations can be useful when grouping by attributes other than Title.

For example, assume that the following software updates titles have been created:

  1. Firmware XYZ version 1.0

  2. Firmware XYZ version 1.1

  3. Firmware XYZ version 1.1.5

  4. Firmware 123 version 4.0

  5. Firmware 123 version 4.1

  6. Firmware 123 version 4.2

  7. Firmware 123 version 4.3

  8. Firmware Super123 version 1.7

  9. Firmware Super123 version 1.8

It is obvious from the titles that the following is true regarding the supersedence of the software updates:

  • Software updates 1, 2, and 3 are superseding versions of the Firmware XYZ update.

  • Software updates 4, 5, 6, and 7 are superseding versions of the Firmware 123 update.

  • Software updates 8 and 9 are superseding versions of the Firmware Super123 update.

Per-User MSI Issues

The Windows Update Agent (WUA) can detect Windows Installer packages on client computers only if they are installed per-system. If an MSI (Windows Installer) rule is created for an update definition and the Windows Installer package was installed per-user, the WUA will be unable to access the user account to detect the package. It is recommended that when MSI rules are used in an update definition, that additional detection rules are configured, such as file versions or registry key values, so that the Windows Installer package can be properly detected whether or not the MSI package was installed per-user or per-system.

When MSI rules are created in Updates Publisher, a message displays that warns about the per-user MSI issue and helps to remind users that creating an update definition with only an MSI rule can result in a Windows Installer package not being detected when it is installed on a client computer. The dialog box warning can be disabled, but it is not recommended. For more information about enabling or disabling the warning dialog box, see How to Disable the Per-User MSI Warning.

See Also