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First of all to get things working, ignore the wireless side of the router, and just operate wired. Later you can sort the wireless once you know you have basic connectivity.
For now wire the modem to the router's WAN port, and the computer to one of the LAN ports. If you power cycle everything, that should now enable you to both get online to the internet with the PC, and also get to the router's configuration menus.
OK, it may be inconvenient to get the PC going wired, and you may have to move the PC temporarily near the modem, but at least you will know that the basics are there. If you can't get a wired connection to see the router's admin pages from the PC, you know that the router/PC or wire between them is the fault. IF you can see the router's admin pages on the PC, but not the internet, the problem has to be the ntl connection or modem, or wire between modem and router.