Installing Silverlight 4 as a User
Installing Silverlight 4 is very easy. For many users, a version of Silverlight might in fact be already installed on their computer. For instance, if you install one of the applications distributed under the label Windows Live (such as Live Messenger, Live Writer, and so on) and keep the default options, Silverlight will be installed on the target PC.
Similarly, Silverlight can be installed by the Windows Update program. This enables administrators to make sure that the latest versions of Microsoft applications are consistently installed in a corporate network. For home users, Windows Update is a great way to make sure that you get notified when a new version of a driver, an application, or a framework (such as Silverlight) is available.
That said, because it is so new, you might not have the latest version of Silverlight and will need to upgrade when you navigate to a Silverlight 4 application in your web browser. Or, you might not have Silverlight installed at all, and here too you will be notified when you reach the page you want to see.
Opening a Silverlight 4 Application
Silverlight applications are always embedded in an HTML page. Opening a Silverlight application for the first time is always a matter of navigating to a web page in a supported web browser.
With the possibility of saving Silverlight applications locally and to run them out-of- the-browser, the startup point might not be a web page anymore, but more classically a shortcut in the Start menu or on the desktop. However, an application may only be installed locally following a user action (for example, a click on a button or a right-click on the application and selecting Install from the Silverlight context menu). It always starts on the web page!
What to Do If Silverlight Is Not Installed?
If Silverlight is not installed at all on the computer you are using (not even an earlier version), you will see an image asking you to install Silverlight, as shown in Figure 1.2. Note, however, that this experience can be customized, and you might see different pages with elaborate designs.
Figure 1.2 Install Microsoft Silverlight.