For reasons I can't fathom, Microsoft removed the ability to delete Wi-Fi networks from the network list if the network isn't in range. Manage Wireless Networks is also gone from the control panel. If you want to better manage Wi-Fi networks in Windows 8, you'll need to head to the command line.
As the screenshot above shows, Windows 8 does have a "Forget this network" option, but it doesn't appear if the network is not in range. To delete old profiles, you'll need to use the netsh command line utility. Raul Castillo writes on TechNet:
Open a run box window (or press win+R) then type cmd to open Windows 8 CLI.
To see stored wireless profiles, type:
netsh wlan show profilesThis will show a list of saved profiles of your connected WLAN devices. Then you'll need to write/save/memorise the profile name that you want to change.
To see the stored key (WPA/WEP/etc) of a specific profile:
netsh wlan show profiles name=[profile name] key=clearYou'll find the key content under security settings.
To delete a stored profile:
netsh wlan delete profile name=[profile name]This will delete the stored profile of every WLAN interface. If you want to delete the profile of a specific WLAN interface, you need to use the following:
pre>netsh wlan delete profile name=[profile name] interface=[interface name]
To set network priority, Albert Xing contributes this command:
netsh wlan set profileorder name="network_name" interface="interface_name" priority=1
The ability to delete network profiles whenever and wherever you are is especially important if there are any public networks you've connected to that are set to automatically reconnect when in range. Hackers love to masquerade as public Wi-Fi networks. If you want to automate the deletion of open Wi-Fi networks in Windows 8, Scott Hanselman has created WiFi.exe, a command line utility to do just that.
Windows 8 - Manage Wireless Networks? [Microsoft TechNet]