If you encounter problems with your D-Link router, it may be necessary to reset it. Resetting the router returns all settings to their factory defaults. Resetting your router can also be useful in the event you forget your router’s username and password.
To perform a factory reset, perform the following-
With the unit on, place an opened paper clip into the hole on the back of the unit labeled Reset.
Hold paper clip down for 10 seconds and release.
The unit will reboot on its own. Once the WLAN light stops blinking, the unit is reset to factory default.
If you’ve modified your router’s settings — such as the operating frequency or channel, and can no longer connect to the Internet, try resetting your router to restore the default factory settings. In some cases, the modifications you make to your router can result in Internet connectivity problems.