WiX woes: What is your installer doing?

Summary: How to detect different modes of installation.

When building an application installer, it's often necessary to distinguish between different modes of installation, i.e. initial installation, repair, upgrade, uninstall, etc. And as with everything important in MSI, detecting the mode of installation is a PITA (and by PITA, I do not mean flat bread of Mediterranean origin). To help you a little bit, here is a table adopted from a StackOverflow topic (and comments), that shows the values of various Windows Installer properties can help you determine the installation mode:

	Install	Uninstall	Repair	Modify	Upgrade
INSTALLED	FALSE	TRUE	FALSE	TRUE	TRUE
REINSTALL	TRUE	FALSE	TRUE	FALSE	FALSE
REMOVE="ALL"	FALSE	TRUE	FALSE	TRUE	TRUE
UPGRADINGPRODUCTCODE	TRUE	FALSE	TRUE	TRUE	TRUE

You can use logical operators NOT, AND, OR to build complex conditions.

Here is how you can detect some common conditions:

First-time installation

• NOT Installed

Any installation

• NOT Installed AND NOT PATCH

Installation and repairs

• NOT REMOVE

First-time installation and repairs

• NOT Installed OR MaintenanceMode="Modify"

Upgrades only (during uninstall phase)

• Installed AND UPGRADINGPRODUCTCODE

Upgrades

• Installed AND NOT REMOVE

Full uninstall (except when triggered by a major upgrade)

• (REMOVE="ALL") AND (NOT UPGRADINGPRODUCTCODE)

Any uninstall

• REMOVE~="ALL"

If you notice errors or want to include some other conditions, please post a comment.

See also:
MSI Property Patterns: Upgrading, FirstInstall and Maintenance
Upgrading, FreshInstall, Maintenance and other MSI convenience properties
MSI Writing Guidelines: Installation Scenarios
How to execute custom action only in install (not uninstall)