How do I distinguish between a normal install and an upgrade in WIX?

Question

I have some custom actions that I only want to execute in an upgrade scenario.

I am trying to set some properties, for example \"MYPROPERTY\"... When I come in via a

Answer 1

I use this in all my setups:

    <SetProperty After="FindRelatedProducts" Id="FirstInstall" Value="true">
        NOT Installed AND NOT WIX_UPGRADE_DETECTED AND NOT WIX_DOWNGRADE_DETECTED
    </SetProperty>
    <SetProperty After="SetFirstInstall" Id="Upgrading" Value="true">
        WIX_UPGRADE_DETECTED AND NOT (REMOVE="ALL")
    </SetProperty>
    <SetProperty After="RemoveExistingProducts" Id="RemovingForUpgrade" Sequence="execute" Value="true">
        (REMOVE="ALL") AND UPGRADINGPRODUCTCODE
    </SetProperty>
    <SetProperty After="SetUpgrading" Id="Uninstalling" Value="true">
        Installed AND (REMOVE="ALL") AND NOT (WIX_UPGRADE_DETECTED OR UPGRADINGPRODUCTCODE)
    </SetProperty>
    <SetProperty After="SetUninstalling" Id="Maintenance" Value="true">
        Installed AND NOT Upgrading AND NOT Uninstalling AND NOT UPGRADINGPRODUCTCODE
    </SetProperty>

You can then schedule your custom action to only run on upgrades:

<Custom Action="NameOfCustomAction" Before="InstallFinalize"><![CDATA[Upgrading= "true"]]></Custom>