MYSQL NOTES:

(1) The MySQL server can be started by double-clicking (executing) mysql_start.bat. This file can be found in the same folder you installed XAMPP in, most likely this will be C:\xampp\.
The exact path to this file is X:\xampp\mysql_start.bat, where "X" indicates the letter of the drive you unpacked XAMPP into. This batch file starts the MySQL server in console mode. The first intialization might take a few minutes.
Do not close the DOS window or you'll crash the server! To stop the server, please use mysql_stop.bat, which is located in the same directory. Or use the fine XAMPP Control Panel with double-click on "xampp-control.exe" for all these things!

(2) To use MySQL as Service for NT / 2000 / XP, simply copy the "my.ini" file to "C:\my.ini". Please note that this file has to be placed in C:\ (root), other locations are not permitted. Then execute the "mysql_installservice.bat" in the mysql folder.

(3) MySQL starts with standard values for the user id and the password. The preset user id is "root", the password is "" (= no password). To access MySQL via PHP with the preset values, you'll have to use the following syntax:

mysql_connect("localhost", "root", "");

If you want to set a password for MySQL access, please use of MySQL Admin.
To set the passwort "secret" for the user "root", type the following:

C:\xampp\mysql\bin\mysqladmin.exe -u root -p secret

After changing the password you'll have to reconfigure phpMyAdmin to use the new password, otherwise it won't be able to access the databases. To do that, open the file config.inc.php in \xampp\phpmyadmin\ and edit the following lines:

$cfg['Servers'][$i]['user'] = 'root'; // MySQL User
$cfg['Servers'][$i]['auth_type'] = 'http'; // HTTP authentification

So first the 'root' password is queried by the MySQL server, before phpMyAdmin may access.