Hi, thanks for using JustAnswer.com I am Cris.
Can you tell me if you have connected any other devices using the same password?
Can you do a power reset of your Kindle to flush out any connections. Press and hold the power button for 20 seconds the device will shut off and then turn back on. When it does try to re-connect and let me know the outcome.
It seems you have the wrong password. Does your PC have a Wireless connection setup?
If so what version of windows are you using 7, 8 or 10?
Do you have a laptop with wireless connection? The reason I ask is because we need to verify the password ***** have.
Who is your internet service provider?
Does the wireless router have a label which states Wireless Key or WEP Key?
Would it be possible to do a remote connection so I can log into your router and verify the password?
If you have the incorrect password ***** will have the same issue.
We need to verify you have the correct password. Authenticationfailed means the password ***** ***** recognized by the router.