Resetting to Factory Defaults
Hardware reset: Push the reset button on the back of the router for 15 seconds.
Software reset:

1. Type 192.168.1.1 in a Web browser.
2. Click on Backup Settings.
3. In the Revert to Factory Default Settings click Erase. IMPORTANT! Do not try to go online, turn off the Router, shutdown the computer or do anything else to the Router until the Router finishes restarting! When the Test light (looks like a check mark) stops blinking, wait a few more seconds before doing anything with the Router.

You will need to check the wireless settings of the router.
Is there any computer online using the router.
check the IP address on that computer.
If yes then you can open the router set up page on that computer.
router set up page is the page where you can check all the router settings.
Click Here for more information about the routers and network