PowerCenter Express ODBC connection to local VM

Hi, I've installed PowerCenter Express and I'm trying to create a connection in the Adminstrator but I'm getting an error.  I'll try to attach the screen shots of the ODBC set up screen and the error message.  I think I just need to set up the ODBC connection string but I've never set one up like this before.  I've got an ODBC configured for use with SQLA called LocTD151, and I've also set up my hosts file to use a hostname of LocTD151.  Any help very gratefully received!
Regards, Jim.