Use the Microsoft Gacutil tool at https://msdn.microsoft.com/en-us/library/ex0ss12c.aspx to install a DLL into the Global Assembly Cache (GAC). For more information, refer to "How to install an assembly into the Global Assembly Cache in Visual C#" at https://support.microsoft.com/en-us/help/815808/how-to-install-an-assembly-into-the-global-assembly-cache-in-visual-c.