New place for proxy server settings
In previous versions of Windows, you changed proxy settings via the Connections tab of Internet Explorer's Internet Options dialog. This still exists in Windows 8.1, but now proxy settings are also available in the Network section of the PC Settings app as well. Open the Settings charm (slide along right of screen or press Win + I), select Change PC Settings, select Network, and select Proxy. It includes most of the same automatic and manual proxy settings found in the Internet Options dialog, with the exception of being able to set different proxy addresses for particular protocols.