Overview

[This is preliminary documentation and subject to change.]

Most users expect that all their installed applications will function properly after they decide to upgrade from Microsoft® Windows® 95 or Windows 98 to Windows NT®. However, it is almost impossible to guarantee that an existing application will work properly after Windows NT Setup completes installation of the new operating system. While Windows NT Setup attempts to adhere to the ideal behavior, there are certain problems with some applications that it cannot resolve. These include problems caused by applications that do the following.

• Write to different registry locations on Windows 95 and Windows 98 than on Windows NT
• Write different registry values to the same registry locations
• Install different run-time files (.dll, .exe, and so on) on the two operating systems
• Install different versions of files that are common to Windows 95, Windows 98, and Windows NT
• Make operating-system-specific calls on Windows 95 and Windows 98 that are not available on Windows NT

As the developer of your application, you are the only one who can resolve these issues. You can use the Migration Extension Interface to interact with the upgrade process and correct inconsistencies like these before they become problems.