When authoring installers it is often necessary to get a log of the installation for debugging purposes. This is particularly helpful when trying to debug file searches and launch conditions. To obtain a log of an installation use the command line msiexec tool:
msiexec /i MyApplication.msi /l*v MyLogFile.txt
This will install your application and write a verbose log to MyLogFile.txt in the current directory.
If you need to get a log of your installer when it is launched from the Add/Remove Programs dialog you can enable Windows Installer logging via the registry.