The .NET Framework installs an Explorer extension that basically allows you to view the installed assembly list, view its properties and uninstall them. The purpose of this extension is to hide the internal structure of the GAC so that users cannot delete or move files from there using the default Windows Explorer and corrupt any of the installed assemblies. However, there are situations where you need to have access to the physical files installed in the GAC folder. This can easily be achieved by assigning a drive letter to the GAC folder. For example if you want to assign drive G, just type the following command in a DOS command line:
subst g: %windir%\assembly\gac
Now, you will be able to access the physical files in the GAC using the default Windows Explorer view. Use it with care.