Just purchased a Nighthawk AC1900 wifi cable modem router model C7000v2

[Christ1st]

Stuck on www.routerlogin.net keep loging in and it goes to same page asking for login

[plemans]

so when you put the login/password in it takes you right back to the same page? 

Have you tried a different web browser and/or PC?

have you tried factory resetting and starting over? 
Push and hold reset for7-15 seconds while powered on.