Wireless network has disappeared !

Question

I have a DI-634m and the Wireless NEtwork has suddenly stopped functioning and is not even listed on the "My Network Connections" list.

Whta could have happened ?

I've looked at the manual trying to reset, and I can't get even get into http://192.168.0.1/ which is the Setup Wizard URL.

I have internet connection through the D-Link box by wire to my desktop.