There are two ways to author the installation database such that an action is only called when the package is uninstalled:

• If the action is sequenced after the InstallValidate action in the InstallExecuteSequence table, the package author may specify a condition of REMOVE="ALL" for the action in the Condition column. Note that the REMOVE property is not guaranteed to be set to ALL during an uninstall before the installer executes the InstallValidate action. Note that the quote marks around the value ALL are required in this case.
• If the action is sequenced after the CostFinalize action and any actions that could change the feature state, such as MigrateFeatureStates action, the action can be conditioned on the state of a particular feature or component. See Conditional Statement Syntax. Use this option to call an action during the removal of a particular feature or component, which may occur outside of the complete removal of the application.

Note that the Installed property can be used in conditional expressions to determine whether a product is installed per-computer or for the current user. To determine whether the product is installed for a different user, check the ProductState property.

Note that older versions of a product may be removed during an upgrade by the RemoveExistingProducts action. The Upgrade table may also set the REMOVE property to ALL in this case. To determine whether a product is being removed by an upgrade, check the UPGRADINGPRODUCTCODE property. The installer only sets this property when RemoveExistingProducts removes the product. The installer does not set the property during a normal uninstall, such as removal with Add/Remove programs.

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Build date: 8/13/2009