I was a bit too fast with my first answer!
You were right, that the SQL Server and SQL Server Agent
must run under an administrative user account.
After changing the configuration, I was able to install
the Workflow Services, but this only a part of the story.
Trying to use the Workflow services via Worklow-Manager
(by connecting to the SQL server), I got the message, that
the Server Version is not supported.
How could I resolve this issue?
By the way, this is the SQL Server Version (German issue):
Microsoft SQL Server 2000 - 8.00.384 (Intel X86) May 23
2001 00:02:52 Copyright (c) 1988-2000 Microsoft
Corporation Developer Edition on Windows NT 5.0 (Build
2195: Service Pack 2)
>What is the exact message that you get?
>Is the SQL Server and SQL Server Agent service running
under the local
>system account? If they are, can you change them to an
>account, and re-run setup?
>Microsoft SQL Server Support