1.-In XAMPP press button Shell
2.-place command:
mysqladmin -u root password
New password: aqui colocar password ejemplo ´09876´
3.-go on the local disk c: xampp \ phpMyAdmin open config.inic.php with notepad ++
5.- add the password and in AllowNoPassword change to false
/* Authentication type and info */
$cfg['Servers'][$i]['auth_type'] = 'cookie';
$cfg['Servers'][$i]['user'] = 'root';
$cfg['Servers'][$i]['password'] = '09876';
$cfg['Servers'][$i]['extension'] = 'mysqli';
$cfg['Servers'][$i]['AllowNoPassword'] = false;
$cfg['Lang'] = '';
6.- save changes, clear browser cache and restart xampp