All wireless routers have a reset button which resets the router back to factory default settings (aka like you just bought it off the store shelf). Under normal circumstances, you do not need to reset the router. However, a situation may arise where you need to reset the router (e.g. forgotten password, wifi or ethernet ports not working, etc.).

What you do is to take a paperclip and bend the end open. You then push that open end into the small hole (or button) and hold the button down for ~30 seconds, then let go. When you let go, you should see the router lights flash on and off. Wait about 3-4 minutes for the router to boot-up, then program the router using the setup wizard.

NOTE: In most cases, the reset button is a small, fragile button. Slowly push the paperclip in to the reset hole/button until you feel it push the button. If you push too hard, you'll just end up breaking the router.