WNDR3400v3 N600 Wireless Dual Band Router password reset instructions don't work

[Strugglin]

I don't understand why when I ran antivirus software it alerted me I have a weak router username and password. I have set a new username and password and have clicked "apply." But when I follow the instructions which are copied>pasted, below, I get to step 2. and it only accepts the *old* username and password to log in as described in step 2. Then when I do step 4 and click on "Wireless," it opens up the page and displays the *new* updated SSID and Passphrases, NOT the *old* username and password I had to type in in step 2. Why do they not match? 
I want to update my "too weak" username and password but it does not appear to be saving it based on going through the provided steps, below.
Even more confusing: Step 6 is not accurate because there is no field with that name. There is a field named "passphrase," but not a field named "Password (Network Key)."
I have clicked the "apply" button but then when I log out and try to log back in again, once again it asks for a username and password but will only take the *old* one, and my antivirus scan repeats that the username and password are still too weak.

Here are the steps NETGEAR offers me online for my model:

Article ID: 23439

To change your WiFi password or network name (SSID):

1. Launch an Internet browser and type http://www.routerlogin.net into the address bar.
   If you are having problems accessing routerlogin.net, visit Router login page cannot be displayed or is blank.
2. Enter the router user name and password when prompted.
   The default user name is admin. The default password is password.
3. Click OK.
   The BASIC Home page displays.
4. Select Wireless.
5. Enter your new user name in the Name (SSID) field.
6. Enter your new password in the Password (Network Key) fields.
7. Click the Apply button.
   Your changes are saved.

[Retired_Member · Accepted solution]

You're welcome

http://www.downloads.netgear.com/files/GDC/WNDR3400V1/WNDR3400_UM_31AUG2010.pdf

Password and passphrase are different ............one is for router security............ and the other is for WIFI security

[Retired_Member]

you cannot change router user ID .................. it's in the manual

[Strugglin]

Thank you for the help. I don't have the manual. So how to change password? Do I just change the "passphrase?"

[Retired_Member · Accepted solution]

You're welcome

http://www.downloads.netgear.com/files/GDC/WNDR3400V1/WNDR3400_UM_31AUG2010.pdf

Password and passphrase are different ............one is for router security............ and the other is for WIFI security