Manufacturers set up all of their new routers with the same default username and password. The username is often simply the word "admin" or "administrator." The password is typically empty (blank), the words "admin," "public," or "password," or some other simple word.
To improve the security of your Wi-Fi network, you should change the administrative password on your wireless access point or router immediately when first installing the unit. The default passwords for popular models of wireless network gear are well-known to hackers and often posted on the Internet. Most devices do not allow the administrative username to be changed, but if yours does, seriously consider changing this name as well.
Finally, to maintain home network security for the long term, continue changing this administrative password periodically. Use words that would be very difficult for others to guess. Many experts recommend changing Wi-Fi passwords every 30 to 90 days.