How It Works

• Developers often split files into archives which are later decompressed by the installer. The installer then lists features that can be installed if the user chooses only to install certain features. The user chooses also what directory to install the files in and the installer decompresses the archives while installing the data to their respective locations and files. Many times, Windows Installer also creates a shortcut in the Start menu and on the desktop if the user chooses to do so.
  
  

Packages

• Windows Installer files are called installer packages. Each one contains features and components. Features in packages are small groups of components. For example, three components called "English Dictionary," "Romanian Dictionary" and "Spanish Dictionary" become available in a feature called "Extra Dictionaries." You can choose which dictionary you want to install as a component or choose not to install the feature at all.
  
  

Benefits

• Windows Installer's development libraries, among other things, come with Visual Studio, which developers use to make applications for Windows. This means that programmers can make an MSI installer right from their own development environment without needing third-party "installer creators." The way Windows Installer packages work makes them very easy for users to manipulate without the trouble of having to understand a great deal about what goes on in the background.
  
  

Features

• Windows Installer keeps a record of what was installed and how it was installed on a user's computer. That way, uninstalling applications is much easier and rolling back to a previous point in time doesn't leave any unwanted data behind to take up hard drive space. Windows Installer also makes it possible for developers to create a "package within a package," meaning that another package can be installed in the middle of the installation of the "main" package.
  
  

Versions

• The first popular version of Windows Installer was released with Windows XP as version 2.0. It shortly became a redistributable version which let developers of applications not released by Microsoft package their own installers for their programs. Microsoft released Windows Installer 3.0 immediately as a redistributable package that came with Service Pack 2 for Windows XP. A few revisions were made that came later with Service Pack 3 for the same operating system. The latest version of Windows Installer as of 2010 comes with Windows 7 as version 5.0