Computer is saying that the correct security key is incorrect

I am assuming that you just got fios or something.

if you have a camera try taking a picture of the password/passphrase and enlarge sometimes they can be tricky in small print. Also caps/lowercase is important. Also if there is a Capital “O” or 0 (zero) try both ways, sometimes look the same.

will it let you connect using wps push button (OS tells you to push the button and there may be a button on the router to hold for about 5 seconds and will sync like bluetooth)

are you clicking on the name of the network and being prompted to enter password or trying to do manualy if so you need to make sure protocal is correct for type and class.

lastly that i can think of make sure you are entering what the OS is asking for
. What I mean by this is that newer routers(gateways) have two passwords, one is a wps pin and other regular password and it is easy to think it is just asking to enter the password when the os is asking to enter the pin (if that is the case it is generally a 8 or 10 digit number on the router as well), or there should be a small choice on the os prompt for the pin to use the password/passphrase instead

please let us know how you are doing