A. In Windows NT 4.0-based domains, the space is a legal character in NetBIOS domain names. Windows 2000 domains are DNS based and therefore use DNS names (although a NetBIOS name is available for backward compatibility). DNS doesn’t allow spaces in names. For consistency, Microsoft removed the space as a legal character in Win2K NetBIOS domain names.

Win2K NetBIOS domain names can contain the following special characters:

   ! @ # $ % ^ & ( ) - _ ' \{ \} . ~ The following characters aren’t allowed:    \ * + = | : ; " ?  ,