My operating system is Windows XP. I have been using Firefox 3.5.7 since it became available and have had no problems. Until today, when I attempted to open my home page. I then tried opening other sites but with the same result a message that reads: The proxy server is refusing connections,
Firefox is configured to use a proxy server that is refusing connections.
Check proxy setting to be sure they are correct.
1. Where can I find my current proxy settings?
2. How can I know what proxy settings are the correct ones.
3. How do I make any changes if necessary?

Do you know why you were using a proxy in the first place? I'd try disabling it entirely.

Go to Tools->Options->Advanced->Connection (Settings) and click on "No Proxy". See if that helps.

Good luck,
WallyH