Avast Home Network Security: Authentication required

I am concerned about the possibility that someone nearby has hacked into the wifi modem in my home. Sometimes my account shows large volumes of Internet traffic on days when my Internet connection has had little or no use at all.
Home Network Security scanned my Asus laptop and alerted me to some vulnerabilities in my system. As i worked through these, I arrived at a screen with the following information:
“Smart Scan
Step 2/3: Network threats
Your router is set to a weak password
Problem
Your router Orcon.Home is set to weak password
Username: admin
Password: admin
Risk
Hackers can connect to the router and modify your network settings, even disabling internet connection.
Catalogue ID HNS-WEAK-PASS
Solution
Change the password in the router settings.
Go to the router settings”
The last line is a link that opens a browser tab with my local IP address in the address bar. The page has the following information:
“Authentication required
http://192.168.20.1 requires a username and password.
Your connection to this site is not private.
User Name:
Password:
[Log In] [Cancel]”
My question is, how can I find out the user name and password that I need to gain access to my router settings? I have tried everything that I can think of. Or is there an another way that I can reset my router password?

factory reset your router and set it up again with a new passoword and network name

google the name and number to find out how to

password generator > https://identitysafe.norton.com/password-generator

some info:
http://www.computerhope.com/issues/ch001289.htm
http://www.howtogeek.com/173921/secure-your-wireless-router-8-things-you-can-do-right-now/

The current access to your router is the default.
User name: admin
Password: admin

Your router [b]Orcon.Home [/b]is set to weak password Username: admin Password: admin
maybe this help > Orcon support

https://help.orcon.net.nz/Technical-Support/Wireless/44711586/How-do-I-change-my-wireless-network-password.htm

https://www.google.no/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=orcon+home+router