How ironic, I've presently got the same issue
What I'm going to do, is use a pin (or pen) and push and hold the little reset button in (I think its 5 secs on mine)
The reset button will be located on the router somewhere (look closely, mines at the back)
Anyway, you will obviously need your Username and password for the Internet to be put back in the settings area, again (in the router)