Mozilla Firefox: Tools > Options > Advanced > Network > Settings
> Manual proxy configuration.
Google Chrome: Options > Under the hood > Network >
Change proxy settings > LAN settings > Use a proxy server > Advanced > HTTP.
Internet Explorer: Tools > Internet options > Connections > LAN settings > Use a proxy server > Advanced > HTTP.
Opera: Tools > Preferences > Advanced > Network.
Google Chrome: Options > Under the hood > Network >
Change proxy settings > LAN settings > Use a proxy server > Advanced > HTTP.
Internet Explorer: Tools > Internet options > Connections > LAN settings > Use a proxy server > Advanced > HTTP.
Opera: Tools > Preferences > Advanced > Network.