You can use the following procedure to delete a file type association. The File Type Associations node is one level below the Application Virtualization node in the Scope pane. When you select this node, the Results pane displays a list of file type associations.
To remove a file type association
In the Results pane, right-click the extension of the file type association you want to delete.
Select Delete from the pop-up menu.
Click Yes to delete the association, or click No to return to the Results pane.