Content Pipeline Page, Project Designer
In addition to the standard Content Pipeline assemblies, XNA Game Studio Express also supports custom assemblies. The Content Pipeline page lists the custom assemblies that are available to the current solution. For more information about custom assemblies, see Overview of the Content Pipeline.
Adding or Removing XNA Framework Content Pipeline Assemblies
Add an assembly by clicking the Add button. Use the Add XNA Framework Content Pipeline Assembly dialog box to navigate to the location of your custom assembly. Select the assembly or assemblies to add, and then click OK. This populates the list displayed on the Content Pipeline page.
Remove an assembly by first selecting an assembly from the list and clicking Remove. This removes the assembly from the list but does not delete the actual assembly.