Test a Silverlight project from Expression Blend
You can verify whether your Microsoft Silverlight 1.0 project is working correctly by building and running it using the Test Project command. A Silverlight 1.0 project is essentially a website project. Consequently, your resulting application will open in your default web browser instead of in its own new window such as for a Windows Presentation Foundation (WPF) project. For more information about Silverlight, see the Silverlight website.
With a Silverlight 1.0 project opened in Microsoft Expression Blend 2, click Test Project on the Project menu, or press F5.
In the Results panel, review the test build process for any errors that may have occurred.
If you encounter an error, a build of the project will be unsuccessful, and you will have to repair the error before you can successfully build the project.
If the test build is successful, your project will automatically open in your default web browser that uses the local development server that is included with Microsoft Expression Studio.
You do not have to have a web server installed to test your Silverlight application. Also, you do not need an active Internet connection, unless you have not yet installed the Silverlight plug-in for your web browser. If that is the case, you will see a message prompting you to download the plug-in (Silverlight 1.0 or Silverlight 1.1 Alpha Refresh) when you test your application.