Power Query unable to connect to MySql

I have installed MySql server on my pc together with MySql connector/ODBC and the Power Query add-in for Excel 2010. I go to "Get External Data from MySql database", where I am asked for Server and Database. I have tried various names for "Server" including localhost, MySql and MySql57; in "Database" I have entered the name of a database that I have created. On the next screen I select "Use alternate credentials" and enter user name and password. When I click "Connect" I get the message "We couldn't authenticate with the credentials provided".

What name am I supposed to enter for "Server"? - as far as I can see, that is the only thing that could be wrong. Any suggestions would be welcome.