wireless network connection doesnt have a valid ip configuration

Typically your best bet is to reset the router. I understand other devices are connecting to it but resetting it may help. You want to find the small reset button on the back and with a paper clip press it in and hold for a couple seconds.

You might need to set the router back up is the only hassle trying this but it is where I would start. Make sure you are close to the router as well so we can eliminate any connection issues due to a poor signal, etc.

 

Is the wireless card itself working properly? Under control panel, device manager? Sometimes you can also reset the adapter by clicking on it, remove device and reboot so it can detect the wireless card again and reset it to factory settings.

Updating the cards driver might help. I can point you to the driver if I have the make and model.