First, you need to make sure that the address is obtained automatically from the phone. To do this, go to Start > Control Panel >Network and Internet > Network and Sharing > Network Adapters (adapters for LAN & Wifi adapters for wireless). Right click the default LAN/WiFi connection, select Properties > IPv4. Make sure the options are set to automatic then reconnect to the phone's network. If it still not working, there is a possibility that the device you use to connect does not support the network mode set on the phone.