Phil has already answered. I'll just post what I wrote a few hours ago
before heading out. The conditions you specify look pretty good to me.
Maybe I'll do a quick review of things that are likely to cause
confusion - such as what custom actions run when?
Major Upgrades: A major upgrade is really an install of a new application version combined with the uninstall of the old version - with different uninstall scheduling possible (uninstall old and install new, or install new and uninstall old). Hence, during a major upgrade operation, 1) the uninstall sequence runs only for the old setup, and 2) the new setup runs only its install sequence. This is of crucial importance to understand what custom actions runs when and why.
Custom Actions and Major Upgrades: To put it in other words: this sequencing can cause quite a bit of confusion for custom action sequencing, since it could appear that an action runs from the new setup, when it in fact runs in the old setup's uninstall sequence. If you are sloppy with sequencing, the typical error is seeing the same action run many times during the upgrade process - potentially twice from each setup (four times in total) - if you run the custom action in immediate mode.
No Retrofitting for Major Upgrades: As Phil explains, you can not add a custom action that will run during the old setup's uninstall sequence inside the new setup. That custom action would have had to be part of the original setup, or added via a minor upgrade (which upgrades the existing installation in-place, rather than uninstall and reinstall it).
Important:
UPGRADINGPRODUCTCODE is set only in a setup that is being uninstalled as part of a major upgrade. It is not set in the new
version being installed.
- The condition
UPGRADINGPRODUCTCODE is hence not true in the installing setup, only in the uninstalling setup.
WIX_UPGRADE_DETECTED is set only in setups that are using WiX's MajorUpgrade element that have detected that another version is
being uninstalled as part of its install.
- The condition
WIX_UPGRADE_DETECTED is hence true in the installing setup, but not in the uninstalling setup.
WIX_UPGRADE_DETECTED: To go into even more detail, WIX_UPGRADE_DETECTED is strictly speaking not a custom WiX feature - it is a WiX standard or convention for setting the built-in MSI property ActionProperty for the upgrade process. All MSI files supporting major upgrades have such a property, WiX just names it in a standard way. The property is set in a column in the Upgrade table, and it is a property that is set when a setup finds related products - that are lower versions (and hence to be uninstalled) - on the same box during installation.
WIX_DOWNGRADE_DETECTED: Note that in a standard WiX-compiled MSI using the MajorUpgrade element there is also WIX_DOWNGRADE_DETECTED - the property used to list products found that are of higher version than the running setup. These would block the setup in question from installing - in most cases (unless the settings are customized by the setup designer).
The action property specified in the upgrade table can be "anything", but the MajorUpgrade Element "convenience feature" does this for you in an "auto-magical" way that makes sense for most purposes - using the mentioned property names WIX_UPGRADE_DETECTED and WIX_DOWNGRADE_DETECTED. Check the Upgrade Table of your compiled MSI to see how this works in detail. Here is a screen shot:
I wrote this other answer showing how to use another property name (YOURUPGRADEPROPERTY) as "ActionProperty": wix installer update process and confirmation dialog (the linked answer is not a recommendation, demonstration only). Just a link, probably not very useful for you now that I think about it.
Some Links:
