I am using visual studio.NET for development of .NET application.<BR>You can use "add reference" to add namespaces(Dll) to your Project.I know the namespace but not able to figure out in which DLL this name space reside.<BR>Can you please let me know a generic tool(Utility) in which i can specify the namespace and output of that utility is DLL Name.<BR><BR>Thanks in advance<BR>I don't know of any tool that does specifically what you are asking but what I use is the ILDASM tool supplied with the sdk. You can then open up the dll and see all namespaces that reside in it.