There are some troubleshooting steps here:
http://www.thegeekstuff.com/2010/08/...nt-connection/
The first two will allow to discover if you have an issue with ports not being forwarded properly or if the remote user is not setup properly depending on the error message you receive.
To troubleshoot the actual tools I would recommend installing the database locally and making sure that works to verify if you have an driver (odbc) issue or something wrong with your configuration file.