I have a problem to make a named pipes connection (TCP/IP is not a
solution in this case) from a Windows
Server 2003 Webserver to a MS-SQL Server (which is not in a
Windows-Domain). If the Webserver is a Windows 2000 computer, then
there is no problem or otherwise if the MS-SQL Server is in the same
Windows-Domain it's also no problem with a Windows
Server 2003 Webserver. What is the solution in my
enviroment?

WINS?

Basically, Windows 2003 has a much stricter policy on named pipes than
previous versions of Windows. Go to Control Panel > Administrative
Tools > Local Security Policy.  Open the Security Options folder, and
under Network Access turn off "Restrict anonymous access to named
pipes and shares" and turn on "Let everyone permissions apply to
anonymous users."

Unfortunatelly the changes in Local Security Policy at the Windows
Server 2003 Webserver had no effect. I assume there is no reboot
required (there was no message, that a reboot would be required).
So the problem is still unsolved.