@ccrause
I only get -1 as errorcode. That's the returncode from SQLConnect, I don't know if i can get any other code.
@zvoni
1) No, the Database is located on an server which is allready running, so no dependences.
2) Yes, I allready tried it. But you brought me onto the right course, I took the wrong user. (local instead of domain user), it works, thank you!