GAC is a central repository (cache) in a system in which assemblies are registered to share among various applications that execute on local or remote machines. .NET Framework provides the GAC tool (gacutil.exe utility), which is used to view and change the content of GAC of a system. Adding new assemblies to GAC and removing assemblies from GAC are some of the tasks that can be performed by using the gacutil.exe utility. GAC can contain multiple versions of the same .NET assembly. CLR checks GAC for a requested assembly before using information of configuration files.

The gacutil.exe /i - is the command that is used to install an assembly in GAC. Users use the Command Prompt of Visual Studio to install an assembly in GAC by using this command.

You can see all the assemblies installed in the GAC using the GAC viewer, which is located at the :\assembly directory, where is windows in Windows XP or windows in Windows Vista or WinNT in Windows 2000. Apart from the list of assemblies, the assembly viewer also shows relevant information, such as the global assembly name, version, culture, and the public key token.