I have reset it many time and each time it has failed to work and there is a password on the router (not admin and password) which I do not know

I am having trouble connecting to myrouterfrom my Xbox and what happens is the adapter has a red light and for a split second will flash green then proceed to go back to red, this happens every few seconds.

At first I thought it was the adapter but I bought a new one today and it continues to do the exact same thing the other adapter did (flash from red to green and back to red).

I have also noticed that when the Xbox is not connected to the router the Wi-Fi says that it has bars that I can connect to but when I do connect the bars disappear and I have no clue what is wrong with it.

Any help would be greatly appreciated.