The global assembly cache is a machine-wide store used to hold assemblies that are intended to be shared by several applications on the machine. The .NET Framework provides a command line tool for working with the cache. It is called the Global Assembly tool (Gacutil.exe).

Installing RichTextEditor into the GAC using Gacutil.exe

From a Visual Studio command prompt, in the same directory where RichTextEditor.dll resides, run gacutil.exe as seen below:

To uninstall an assembly from the GAC, type the following command at the command prompt:
gacutil /u <fully qualified assembly name>

Adding and removing RichTextEditor to GAC manually

You may also directly copy the dll files to the C:\WINDOWS\assembly (or C:\WINNT\assembly) folder of your server - this is equivalent to the gacutil.exe utility.

To uninstall an assembly from the GAC:

1. Navigate to the GAC, which is located at %systemdrive%\Windows\Assembly.
2. Right-click each assembly file that is included in your application, click Uninstall, and then click Yes to confirm.

To check whether this action was successful, click on "View List of Assemblies in the Assembly Cache" in the same pane and check the RichTextEditor.dll.

How to add a reference to the assembly in the GAC?

The proper version number should be inserted into the <assemblies> tag of either the web.config or machine.config file:

After that you should be able to use the control in all the application on the server without having to copy it to the /bin folder of each web application.