If you are having problems with your router that restarting it does not fix, cannot remember the password for your router, or if it is a used router, it is a good idea to reset it to default settings. Routers contain a vast number of settings and by resetting it you can save a lot of time and effort in resolving issues.
On the back of most routers, there is a small reset button which usually requires a pen to push. With the power plugged into the router so that the lights are on, hold the reset button in for twenty seconds and then release. A router which does not work even after being reset almost always needs to be replaced.If you are having problems resetting your router, please check with the manufacturer, as they will have detailed instructions for your specific model.
Once you reset your router you will need to reconfigure or reprogram your router setting to ensure it operates correctly and does not pose a security risk for you. Please follow the instructions located in the following link Configuring Your Wireless Router.