Hello and thank you for using JustAnswer. My name is Kevin - thank you for giving me the opportunity to help you with your networking question.
Just in case you would like to retrieve your password before resetting, here is the correct way to get it:
Use the computer directly connected to the router. Open Internet Explorer and enter this address: http://192.168.0.1/
Select the Admin username and leave the password blank - just click to log in. If the login fails, proceed to the reset steps. If the login worked, click Wireless Settings on the left side. Your Pre-Shared Key, (wireless password) will be listed on this page.
Power off the modem and computer connected to the router. Press and hold the reset button on the back of the D-Link with a pen for 15 seconds, then release. Power it off after it restarts.
Power on the modem - wait 60 seconds
Power on the router - wait 60 seconds
Power on the computer
Open Internet Explorer and enter this address: http://192.168.0.1/
Select the Admin username and leave the password ***** - just click to log in.
Click Wireless Settings on the left side and make these changes:
Wireless Network Name - this is the name of your network. Make it something you have not used in the past.
Security Mode - WPA-Personal
WPA Mode - Auto
Cipher Type - TKIP and AES
Pre-Shared Key - this is your wireless password. Must be at least 8 characters in length, anything you would like to use is fine.
Save the settings and exit. Reconnect your wireless devices to your new network name and pre-shared key. If you have any questions on how to do this part, please let me know.