DI-514 DLink Router

Go to control panel>network connections, right click, then properties, then click the TCP/IP line, properties again and ensure that 'obtain ip address automatically' is ticked, click ok,  then close down the window, right click on the network icon again and then properties, then view wireless connections.

Any that appear in this list including your own if it shows need to be deleted, then when you close the window a pop up should appear in the task bar saying wireless networks detected, click the bubble then highlight your connection, click connect and if security is turned on you will be prompted to enter the passkey.

In the routers settings ensure that DHCP is enabled to allocate ip addresses automatically, then reboot the router if neccasary.