http://www.thewindowsclub.com/how-to-configure-proxy-server-settings-in-windows-8-1
To configure the proxy settings in Windows 8.1, first bring up the charms-bar by pointing the mouse cursor to the lower-left corner of your computer screen or by using Keyboard shortcut – Win+C. Choose ‘Settings’ icon and select the ‘Change PC Settings’ option.
You can now proceed and fill in the IP address, port of your proxy server.
To configure the proxy settings in Windows 8.1, first bring up the charms-bar by pointing the mouse cursor to the lower-left corner of your computer screen or by using Keyboard shortcut – Win+C. Choose ‘Settings’ icon and select the ‘Change PC Settings’ option.
Next, select the option from the left-pane that reads as ‘Network’. It is under this category where proxy settings are hidden.
Scroll down until you find ‘Manual Proxy Setup’ section.
Under that section slide the bar in opposite direction to turn on ‘Use a proxy server’ option.
