[This is preliminary documentation and subject to change.]
Many applications work identically under Microsoft® Windows® 95, Microsoft® Windows® 98, and Microsoft® Windows NT® 5.0. Your application may operate differently under the different versions. If so, if your users decide to move from Windows 95 or Windows 98 to Windows NT, they will be unable to use your application. To prevent this, Microsoft provides the Migration Extension Interface.
If applications do not work properly, users have to reinstall them. Individual reinstallation of applications is an irritation at any level. In corporate environments, where large-scale deployments are automated, reinstalling applications is prohibitive since it increases deployment costs. For most non-corporate environments, users may not have the original installation media readily available to reinstall their applications.
The Migration Extension Interface is an extension to the Setup API that enables you to ensure that your application will operate correctly after Windows NT is installed over Windows 95 or Windows 98. To make use of the Migration Extension Interface, you must write a migration DLL (MIGRATE.DLL) that the Setup program can use to make the changes that will enable your application to work correctly under the new operating system.
This reference is divided into the following sections: