Directly add a reference to an assembly from a GAC.

1. To do this you have to create another folder say "C:\MyAsemblies" and put your dll to this folder.
2. Add a new registry key say "MyAssemblies" to registry "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NetFramework\AssemblyFolders" and set its default data value as "C:\MyAssemblies".
3. Now your dll will be visible in "Add Reference" window in .Net Tab.