The initial login for the router is the following.
IP:192.168.0.1
User: Admin
Pass: (blank)
If this does not work, try disconnecting everything from the router and doing the reset again. Then connect a single computer to it by ethernet. Type the IP into a current version of the browser. Some browsers may report the page as not secure because of the lack of HTTPS on the router, and if this is the case, you will have to go through the browser's process to connect.
This is an old piece of equipment so it may also be time to replace it.