[This is preliminary documentation and subject to change.]
Applications that do not survive migration from one version of Microsoft® Windows® to another will not comply with Windows logo requirements. Your migration DLL can help to preserve your logo compliance.
The Setup program attempts to detect conflicts that arise from implementing your application under the new operating system. It may or may not succeed in identifying inconsistencies. Because of this, you should test your application extensively under various migration scenarios.
The migration functionality is provided to enable you to ensure that your customer base can use your application under the new operating system. You should test how your application behaves under different versions of Windows. Ideally, it behaves the same under different versions.
If conflicts exist, you have two options. You can either correct the intrinsic problem so that no problems occur during migration, or you can create a migration DLL. If you do not take advantage of the Migration Extension Interface, your customers will need to reinstall your application for it to run correctly under the newly installed system.
Migration DLLs must be thoroughly tested before being distributed to end users by means of the World Wide Web or other media. The following procedures outline the minimal process you should undertake during your test. Note that you should repeat the tests for multiple user account scenarios (that is, default, roaming, workgroup, and domain users). The scenarios should also cover combinations of these user accounts.