<!-- truth table for installer varables (install vs uninstall vs repair vs upgrade) https://stackoverflow.com/a/17608049/1721136 -->
<SetProperty Id="_INSTALL" After="FindRelatedProducts" Value="1"><![CDATA[Installed="" AND PREVIOUSVERSIONSINSTALLED=""]]></SetProperty>
<SetProperty Id="_UNINSTALL" After="FindRelatedProducts" Value="1"><![CDATA[PREVIOUSVERSIONSINSTALLED="" AND REMOVE="ALL"]]></SetProperty>
<SetProperty Id="_CHANGE" After="FindRelatedProducts" Value="1"><![CDATA[Installed<>"" AND REINSTALL="" AND PREVIOUSVERSIONSINSTALLED<>"" AND REMOVE=""]]></SetProperty>
<SetProperty Id="_REPAIR" After="FindRelatedProducts" Value="1"><![CDATA[REINSTALL<>""]]></SetProperty>
<SetProperty Id="_UPGRADE" After="FindRelatedProducts" Value="1"><![CDATA[PREVIOUSVERSIONSINSTALLED<>"" ]]></SetProperty>