Please ensure your PC is set to obtain an IP address automatically. Then try to renew your IP via command prompt.
If that doesn't work, try to reset the router by holding down the reset button located in the back for 15 seconds and repeat the steps above.
And if that still doesn't work.. static enter in an IP address for your PC and try to access the router.
For example:
PC: 192.168.0.X (X= any number from 2-254)
Router IP: 192.168.0.1 (By default)