Netgear AC1900 Smart Router

Want to change the Password of Netgear Router and when i try to access the webpage routerlogin.net then it shows an error. Please help me to access the netgear router login page.

I was experiencing some problems with our 2 year old UN55ES7100 Samsung 3D TV with Netflix, so I decided to replace my 10 year old Linksys WRT54GS Wireless G Broadband router. I installed a new Netgear Nighthawk AC1900 Smart WiFi Router. Our 2 I-phones and 2 I-pads lit up in about 5 seconds...