Server applications should store version information in their native data format. Version checking should be performed by the setup program as well as by the server application. You can use the File Installation Library, VER.DLL, supplied with Microsoft Windows Version 3.1 to extract a version string from the application. For more information on VER.DLL, see the Microsoft Windows Programmer's Reference, Volume 1: Overview in Version 3.1 of the Microsoft Windows Software Development Kit.
If a new version of a server application allows the user to keep the old version available, a new key class name should be allocated for the new server. One way to do this is to append a version number to the key class name and class name human-readable value. This allows the user to easily differentiate between the two versions when necessary.
When the new version of the server is installed, the user should be given the option of either mapping the old objects to the new server (registering the new server as the server for both class names) or keeping them separate. When the user keeps them separate, the user will be aware of two kinds of objects (for example, "Graph1" and "Graph2")