MySQL 3.23 is a very old version; the current recommended release is 5.0. Version 3.23 will still work, but you will miss out on a number of features and bug fixes added in the last few years.
The MySQL manual provides a good explanation of the possible issues:
"The error (2003) Can't connect to MySQL server on 'server' (10061) indicates that the network connection has been refused. You should check that there is a MySQL server running, that it has network connections enabled, the network port you specified is the one configured on the server, and that the TCP/IP port you are using has not been blocked by a firewall or port blocking service."
This was first published in August 2006