I have the latest 64 bit version of PostgreSQL. I am running Win 7 64 bit. I had installed the ODBC driver (via the initial installer) when I installed PG, and upgraded it to the latest version from http://www.postgresql.org/ftp/odbc/versions/msi/.
However, when I go to the ODBC control panel and try to add a User DSN, PostgreSQL isn't listed as a server.
I was following the instructions given here, but I noted the links are dated.