You may proceed with  the following troubleshooting steps and it shouldn’t take you much longer  than 15 minutes.

1. Please standby a computer/laptop to  access to the internet and connection must be via LAN cable (connect the LAN  cable to the Black port at D-Link Router and direct to the computer/laptop).

2. You may open any web browser such as  Google Chrome, Internet Explorer, Mozilla Firefox and etc.

3. On the address bar, please go to http://dlinkrouter.local./ and below  page will appear. (These are the defaults and if you have done a  configuration on your router previously, the password may be different)

Username: admin

Password: (Leave the field blank)

4. Once you have  successfully login, the router's web-based setup page will appear. Please follow below steps for the configuration.

5. From the top menu, click Settings and then choose Wireless.

6. Below screen will  appear to configure the wireless setting. Since this is a dual band router,  you will have 2 Wi-Fi Names (SSID); i.e. 2.4GHz and 5GHz.

i. For 2.4GHz setting, click Advanced Settings to display more available options.

ii. To change the  channel, click the drop-down arrow for Wi-Fi Channel, then select your desired channel.

Choose between 1 to 13 (Suggested channels : 1,6,11). Click Save for the changes to take place.

The router will auto reboot and connection will re-establish after few  minutes.

iii. Next, for 5GHz  setting, click Advanced Settings  to display more available options to make changes on the wireless channel for  5GHz.

iv. Click the  drop-down arrow for Wi-Fi Channel, then select your desired channel from the selection.

v. Click Save for the changes to take place.  The router will auto reboot and connection will re-establish after few  minutes.