Installing forum PHPBB...error

[chasoft]

Hello, is there anybody help me? I'm a newbie on web field, I want to setup a server on my PC running PHP and support MySQL.... I did something successfully BUT... I have some problems with daabase. Please view my description:

Installed IIS successfully -> http://localhost -> okie
Installed PHP successfully -> <?php phpinfo(); ?> ->okie
Installed MySQL Server 5.0 successfully

Then, I create a database
mysql> CREATE DATABASE mydatabase1
mysql> Use mydatabase1

then, I create a user

mysql> GRANT ALL PRIVILEGES ON *.* TO 'myaccount'@'localhost'
-> IDENTIFIED BY 'mypass' WITH GRANT OPTION;
mysql> GRANT ALL PRIVILEGES ON *.* TO 'myaccount'@'%'
-> IDENTIFIED BY 'mypass' WITH GRANT OPTION;

Then, I install the forum phpBB
---Basic Configuration---
Default board language: English
Database Type: MySQL 3.x or MySQL 4.x or MS SQL Server 7/2000 or MS SQL Server [ ODBC ]
Choose your installation method: Install

---Database Configuration---
Database Server Hostname / DSN: localhost
Your Database Name: mydatabase1
Database Username: myaccount
Database Password: mypass
Prefix for tables in database: phpbb_

BUT... when i click "Start Install" button, there is error

(When I use MySQL 3.x or MySQL 4.x or MS SQL Server 7/2000 )
An error has occurred during installation
The PHP configuration on your server doesn't support the database type that you chose


(When I use "MS SQL Server [ ODBC ]")
phpBB : Critical Error
Could not connect to the database

- - -
Please help me in detail. I look forward to receiving your reply.

Thank you in advanced.