A. While the DNS server supplied with Windows 2000 supports the underscore (_) character as a valid DNS character (in accordance with RFC 2181) other DNS solutions may not and so to avoid possible problems Windows 2000 changes any _ to a - in a computer name during setup.

After Setup is complete, you can change the computer name back to include the underscore. If you do so, you receive a warning that the computer name may not work.