You can find the connection settings in Tools > Options > Advanced : Network : Connection

See "Firefox connection settings":

• Firefox can't load websites but other browsers can

Yes, that is were I have to make the change every time I open up Firefox. I doesn't let me set it as the default. Do you know where I can go to set Auto-detect as the default so that when I open up Firefox Auto-detect is already chosen?

thanks I deleted the items from the js file so that it now saves my preferences so thanks.

I had the same problem, changing the proxy setting did not worked. After I uninstalled Firefox 4 rc2 and removed all the old Firefox folders I did a fresh installation of Firefox. The problem was solved. So probably something went wrong during the upgrade from version 3.6.15 to version 4.0 RC2.

Don't forget to remove all the folders in c:\users\UserName\AppData\Roaming\Mozilla

I did uninstall Firefox and installed the latest version but I still have the same problem with settings set to manual proxy instead of auto-detect. Did I need to delete my personal settings as well like bookmarks before installing the newest version?

Hello Richard, Download MozBackup and make a backup of your bookmarks and passwords. Uninstall firefox and remove ALL folders with the name "Firefox". Install Firefox and restore your bookmarks and passwords. Now you should have a fresh install so you have to make all settings again.