I pressed the reset button with a needle, logged in the router interface, reset the wireless key, disabled/enabled DHCP, re-entered the internet connection information and lastly recreated the wireless connection in my computer.
Go to D Link site. if your model got a firmware upgrade do that.
Upgrade your wireless card drivers to latest one.
Make sure when you upgrade firmware, you have no risk of power loss to the router. Do it at a time when you have the least risk of load shedding or on a backed up power like UPS/generator etc.