Ray-Am attempting to install Firefox 2 and an update to another program and receive the message "The proxy server is refusing connections. Firefox is configured to use a proxy server that is refusing connections." What must I do to allow these installations?

I don't know.  Hopefully, someone else will know.

Look under tools\options\advanced\network\settings and see what proxy server that Firefox is attempting to use. [This is in the Firefox browser.]
If you are using a proxy perhaps you have it configured incorrectly.
The connection settings in the browser should match your Internet connection method. Note that there is an option to auto detect the network settings.