Microsoft Knowledge Base Article 249841 contains the following summary:
Site awareness is a key feature in the Active Directory Client Extension (DSClient).
This article describes new Microsoft Windows 98 behavior in
locating domain controllers when the DSClient is installed and the user is
logged on to a Microsoft Windows 2000-based domain.
Note You must install the Windows 98 DSClient package to use of the functionality that is described in this article.
For additional information about installing the appropriate Active Directory Client Extension, click the following article number to view the article in the Microsoft Knowledge Base:
How to install the Active Directory Client Extension
Note The Active Directory Client Extension has been updated. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
323466 Availability of the Active Directory client extension update for Windows 98