We have several options when it comes to handling prerequisites needed by our installer. When I say prerequisites, I mean frameworks such as .NET, databases such as SQL Server, and the environment itself such as having the expected version of Windows. We can stop the installation outright if our requirements aren't met. On the other hand, in some cases, we may choose to download the missing items. For example, if the end user is missing the .NET Framework, we can install it prior to installing our own software.
In this chapter, we'll cover several scenarios, including how to prevent installations to the wrong environment, download components from the Web, and install either 32-bit or 64-bit files depending on which architecture the operating system supports.