MS SQL Server: NT Authentication. Possible?

[Dirk Hagemann]

> 	You have a user named "null"?
>
> 	Off-hand, it looks very much like the CGI script is still running
> with the privileges of the web-server, and /that/ is set up in a locked
> down account that doesn't have connection rights.

I also thought this might be the reason, but when I include
username = os.environ.get('REMOTE_USER')
in this script and print the username, it's my NT-username and not a
webserver user.
By the way - the webserver is an IIS.
I once before had the problem that some code worked fine when I
directly executed it, but didn't work when executed by this webserver
(both again with the same user-account).
May be it has something to do with the IIS. I will try to find a
solution by reading these sites:
http://www.google.de/search?hl=de&q=%22Login+failed+for+user+'(null)'%22+%22Not+associated+with+a+trusted+SQL+Server+connection%22&btnG=Suche&meta=

Dirk