Silverlight is a plug-in that facilitates rich-media application for your browser. Netflix, for instance, used Silverlight technology to deliver live-streaming movies and videos.

Earlier versions of Silverlight focused on streaming videos and was seen as a possible replacement for Adobe Flash (formerly Macromedia)'s technology, although the newer versions focus more on multimedia animation.

Some users have reported certain issues with newer versions of Silverlight working properly with Netflix and uninstalling version your current version and installing Silverlight 3 might be a fix to look at.