If you get a Network Encryption error, this is caused when attempting to connect to a WEP network.
Your router's settings will need to be changed over to WPA/WPA2 encryption.
Most routers will have the option to be set to WPA/WPA2.
Instructions on doing so can vary depending on the manufacturer of the router and model. If you require assistance changing this over, it is suggested that you contact your Internet Service Provider (ISP) or the manufacturer of the router.