Whenever Windows Installer’s built-in actions do not suffice to perform a specific task, a Custom Action needs to be written. Needless to say, Custom Actions, can be a bit tricky – not only can they be laborious to write and cumbersome to debug, they also run the risk of interfering with Windows Installer’s declarative, transactional way of performing installs. It is not really surprising that Windows Installer therefore more or less discourages the use of Custom Actions unless it is absolutely necessary.
Almost two years ago, I wrote about how to create multi-language MSI packages. Although using transforms to internationalize an MSI package is a viable solution, one drawback of this approach is that it may require a bootstrap loader. While it is easy to say that a bootstrap loader is required and many high-profile setups do indeed use bootstrap loaders, bootstrap loaders do have their issues. They not only add complexity to the setup package, there actually are several reasons why a bootstrap loader-free setup may be preferrable.