Build the Installation Program Immediately

Begin developing the installation program immediately after you start developing your project. The installation program is the first part of your product that your users see. Too many products give a poor first impression, showing that the installation program was left to the last minute. By getting the installation program started as early as possible, you have sufficient time to test and debug it. If the installation program is done early, you can also incorporate it into your smoke test. This way, you're always testing it, and your tests will be one step closer to simulating how the users will be running your program.

Earlier in the chapter, I recommended that you should build both release and debug versions of your product. You also need to have an installation program that allows you to install either version. Even though managed applications are supposed to support XCOPY installation, that's only for toy programs. Real-world managed applications are going to have to initialize databases, put assemblies in the global assembly cache, and handle other operations that just can't be done with a simple copy. By having a debug build installation program, developers can easily get a debug version on a machine so that they can quickly start debugging a problem.

One extra benefit of having the installation program done as early as possible is that others in your company can start testing your program that much sooner. With the installation program done, the technical support engineers can start using your program and providing you with feedback early enough in the cycle so that you can actually do something about the problems they find.

Back in the "Wonderful MSBuild" section, I mentioned several tasks for using the Windows Installer XML Tool Set (http://wix.sourceforge.net/). It is Microsoft's first big open source project and is an excellent tool for building setup applications. Like many open source projects, it lacks great documentation, but if you can work your way through it, you'll be rewarded with an installation that becomes part of your development process. If you're worried about the scalability of WiX, rest assured that it can handle anything you throw at it. For example, WiX builds the Microsoft Office and Microsoft SQL Server 2005 installations.

I strongly suggest that you give WiX a very hard look for your particular applications, no matter what type of development you are doing. You can look at my installation program, which is built using WiX as an example. If you're brand new to WiX, the best place to start is with the outstanding WiX Tutorial from Gábor Deák Jahn at http://www.tramontana.co.hu/wix/.