Can not create open silverlight 2 projects "Object reference not set to a instance of an object"

If you install Visual Studio 2008 Service Pack or .NET 3.5 Service Pack, then the Silverlight Projects may not be working properly.

Problems:
When you create a new silverlight project you get a message "Object reference not set to a instance of an object"
When you try to load existing project it tells that visual studio can not open this type of project.

Solution:

1. Open the command prompt and go to the folder
   C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE
2. type devenv /resetskippkgs
3. close the Visual Studio Window that will open after completion of previous command.
4. type devenv /setup
5. After the execution of previous command is complete open Visual Studio.