In the default installation of WAMPServer phpmyadmin is setup to use the 'root' userid with the default empty password.
Once you change the password on the 3 mysql root accounts you have to amend the phpmyadmin configuration.
There are a couple of options :-
Edit \wamp\apps\phpmyadminx.y.z\config.inc.php
Find this line
$cfg['Servers'][$i]['password'] = '';
And put the new password in the quotes
$cfg['Servers'][$i]['password'] = 'MY_NEW_PASSWORD';
Second option, my prefered, and more secure in my opinion
Edit \wamp\apps\phpmyadminx.y.z\config.inc.php and change it to this
/*
* First server
*/
$i++;
/* Authentication type */
$cfg['Servers'][$i]['verbose'] = 'mysql wampserver';
$cfg['Servers'][$i]['auth_type'] = 'cookie';
//$cfg['Servers'][$i]['auth_type'] = 'config';
//$cfg['Servers'][$i]['user'] = 'root';
//$cfg['Servers'][$i]['password'] = '';
/* Server parameters */
$cfg['Servers'][$i]['host'] = '127.0.0.1';
$cfg['Servers'][$i]['connect_type'] = 'tcp';
$cfg['Servers'][$i]['compress'] = false;
/* Select mysql if your server does not have mysqli */
$cfg['Servers'][$i]['extension'] = 'mysqli';
$cfg['Servers'][$i]['AllowNoPassword'] = false;
This will cause phpmyadmin to throw a login page, so there is no password held in the file so nobody can get your root users password by viewing the file.
Also you can then use any User account you setup in MySQL to run phpmyadmin, you are not limited to just the root account, useful for testing that other accounts you setup have the correct privileges
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(Windows 10 Pro 64bit) (Wampserver 3.3.4 64bit) Aestan Tray Menu 3.2.5.4
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