How to move a dll file to the Global Assembly Cache

The Global Assembly Cache tool allows you to view and manipulate the contents of the global assembly cache and download cache.

This tool is automatically installed with Visual Studio and with the Windows SDK. To run the tool, we recommend that you use the Visual Studio Command Prompt or the Windows SDK Command Prompt (CMD Shell). These utilities enable you to run the tool easily, without navigating to the installation folder.
For more information, see Visual Studio and Windows SDK Command Prompts.

    If you have Visual Studio installed on your computer: On the taskbar, click Start, click All Programs, click Visual Studio, click Visual Studio Tools, and then click Visual Studio Command Prompt.

    -or-

GacUtil is part of the Framework SDK. the 1.1 version is located at C:\WINDOWS\Microsoft.NET\Framework\v1.1.4322

    If you have the Windows SDK installed on your computer: On the taskbar, click Start, click All Programs, click the folder for the Windows SDK, and then click Command Prompt (or CMD Shell).

    At the command prompt, type the following:

gacutil [options] [assemblyName | assemblyPath | assemblyListFile]

The following command installs the assembly mydll.dll into the global assembly cache.

           gacutil.exe -i "mydll.dll"

The following command removes the assembly hello from the global assembly cache as long as no reference counts exist for the assembly.

          gacutil.exe -u "hello.dll"