Question : What happens exactly when you rest a router?

Hello all, I am haveing some trouble here , lol.  My parents and i moved to germany about 6 years ago and when we got here we received this  Speedport 500W router , which is a german router . My parents have forgotten their password . And they Will not let me reset the router  until i can tell them exactly what settings would  be reset. Would the internet stop working completely? , what would happen? so basicly they are scared that if i rest the router , that we would not be able to connect to the internet.
I thank you in advace :)

~Maniai

Answer : What happens exactly when you rest a router?

Yes, it is possible that if you reset the configuration you will lose connectivity.

For example, it could have a static IP address, or use PPP authentication which requires a username/password. In most cases, however, any parameters such as these should be available (or already in possession) to the customer.