I cannot connect. I keep getting a message "authentication Failed"

Do you connect your PC to router in an administrator role using web browser? Or do you connect some device to Wi-Fi network?

1. Administrator role: You need to have correct login name and password for admin access. Search in manual or ask Google for default login name and password of your router type. If non-default password is set in the router then you must reset router setting and erase its settings to default (factory) status. You will lose all router configuration but default password is back.
   
2. Wi-Fi client role: There are more possibilities why authentication fails in wireless communication. Mentioned error message describes what kind of problem occurred.
   (a) A password you put to client device does not match the wireless network password which is set in router. Your computer, tablet or smartphone WI-Fi interface must have exactly same password as WI-Fi network which is transmitted from router. Check and compare passwords on both sides, in client device and in router.
   (b) Client Wi-Fi interface security (encryption) mode differs from Wi-Fi network encryption used in router. But the same mode must be set on both sides (client and router) for successful connection.

• WPA2 Enterpise
• WPA2 PSK ("home")
• WPA Enterprise
• WPA PSK
• WEP
• No encryption (open)