Put generated password in config.inc.php if you changed root user password. I was repeatedly putting password that it asks in phpmyadmin and not generated password.
Being a noob in php and just starting out in xampp, I changed root user password and phpmyadmin has generate password button which generates password that's suppose to get updated in config.inc.php files line but it didn't so I manually updated it.
$cfg['Servers'][$i]['password'] = 'dRHfGtwfJXhzC96M';
On the other hand, this might also help, it involves adding a line to resetroot.bat