After you install Windows, you may receive critical and non-critical error messages. You may receive error messages in both Windows 2000 and your previous version of Microsoft Windows NT 4.0, Microsoft Windows 98, or Microsoft Windows 95 (any version of Windows that uses the Program Files folder).
Version of Windows that are not affected are Microsoft Windows 3.x, Microsoft Windows for Workgroups 3.1x, and Microsoft Windows NT 3.x.
This behavior can occur if Windows 2000 and your previous version of Windows are installed on the same partition. This causes certain folders to be shared by different operating systems or by programs installed in those operating systems.
You should install Windows 2000 on a partition that does not also contain Windows NT 4.0, Windows 98, or Windows 95. You cannot have Windows 2000 and Windows NT 4.0, Windows 98, or Windows 95 on the same partition; this configuration is not supported
Version conflicts can arise when shared files are used by multiple operating systems. Some common components that cause these problems are files located under the Common Files folder, Microsoft Internet Explorer folder, Microsoft Outlook Express folder, specific program folders, other Internet-related components, and the Accessories folder. Each operating system may install its own version of a file in the shared folder. This file may not work under the other operating system. Programs may install operating system-specific files that do not work properly in the other operating system.