There are 2 ways to install an assembly into GAC. 1. Simply Drag and Drop your assembly into correct GAC Location based on your .NET framework2. Use GacUtil.exe (GAC Utility Tool) E.g. execute following command into our visual studio command prompt Gacutil -i C:\SampleProject\SampleAssembly.dllGood to know: To install an assembly into the GAC, the assembly must be strongly named, otherwise you get an error stating - failure adding assembly to the cache: Attempt to install an assembly without a strong name. To uninstall assemblies from GAC run the following command Gacutil -u MyClassLibrary