For Netscape go to Edit => Preferences => Advanced. Double click on Proxies. Put a mark in the "Direct Connection to Internet" button. Press OK.
For Opera go to File => Preferences => Connections => Proxy Servers. Uncheck all check boxes. Press OK, then OK again.
For all Browsers, exit the browser after the change and re-start it. No re-boot is required.
Should you find that surfing with your browser unproxied seems slower, simply go back and put the check mark back in the box.
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