WiX how-tos and missing links

Summary: Links to articles explaining how to accomplish different tasks in WiX and other helpful information.

This is post #4 of the six-part Learning WiX series. For other topics, see:

Table of contents

1. Background (why WiX?)
2. Introduction (answers to common questions)
3. Getting started (references and tutorials)
4. How-to's and missing links
5. Slides and demo projects
6. Improved demo projects (32- and 64-bit installers)

Here is a list of articles covering topics that I either did not find -- or found implemented better than described -- in most popular WiX tutorials and wikis:

How to: Exclude license agreement dialog from the dialog sequence
How to: Install a Windows service (see also this and that)
How to: Build 32-bit and 64-bit MSI packages (see this thread, and that one, too)
How to: Add a shortcut (without an icon [.ICO] file)
How to: Add a checkbox to conditionally install a desktop shortcut (via a check box)
How to: Add a desktop shortcut (without a registry key)
How to: Create shortcuts for ALL USERS
How to: Execute custom action (CA) on uninstall only
How to: Create an uninstall shortcut
How to: Launch program after installation
How to: Add a neat checkbox to the exit dialog for launching a program or help file
How to: Create a localized installer and bootstrapper (see also parts 2, 3, and 4)
How to: Modify XML files (e.g. web.config) during installation
How to: Modify web.config file during installation (turn off debug flag, etc)
How to: Implement custom actions (CAs) (excellent explanation of different CA types)
How to: Implement a custom action in managed code (C#/VB.NET)
How to: Implement a major upgrade (see Brian Gillespie's comment for optimization ideas)
How to: Preserve original Windows service configuration on major upgrade
How to: Deploy a web site (also this one)
How to: Save path to installation folder in the registry (search for ARPINSTALLLOCATION; see also this, this, and that)
How to: Override (wrong) Program Files (x86) on x64 machines in WixUI_Advanced sequence
How to: Upgrade application in the original installation folder ()
How to: Make setup UI sequence show only two (Welcome and Final) dialog boxes
How to: Retain user-customized files during a Windows Installer major upgrade
How to: Register a COM+ application
How to: Create an event log source
How to: Deploy publisher policy files to GAC

I also found the following information very insightful (some related to MSI, other about WiX):

Description of TARGETDIR and SourceDir
Explanation of the MergeRedirectFolder variable
Differences between 32-bit, 64-bit, and mixed MSI packages (includes folder locations, package compatibility and other info)
How Windows Installer Processes Packages on 64-bit Windows
List of system folders defined by the Windows Installer engine
Add/Remove Programs (ARP) support (good explanation and illustration of ARP properties)
Windows Installer: Property Reference
MSI Writing Guidelines

I will keep updating these lists updated when I find more useful articles.

See also:
WiX - Windows Installer XML (more how-tos)
WiX tricks and tips (includes a few how-tos)
WiX Tricks (several good suggestions)
WiX Tips & Tricks