Question : We are unable to access database using following parameters.

osDate 2.5 Installer  - Fresh Install
We are unable to access database using following parameters. Please check the parameters and retry.
Step 2: New Database Configuration
The osDate installer needs some information about your database to proceed with the installation. If you do not know this information, then please contact your website host or administrator. Please note that this is probably NOT the same as your FTP login information! Required fields are indicated by *
Database Host: *       (Usually "localhost")
Database Type: *       
Database Name: *       
Database User: *       
Database Password: *       
Table Prefix: *       

Answer : We are unable to access database using following parameters.

below is an osDate requirements:
Requirements
·      PHP 4.3.0 or higher
·      PHP safe mode must be turned off
·      MySQL 4.0 or higher
·      Ability to change the permissions of files and folders
·      PHP GD or GD2
·      Flash 7 Player or higher

So easiest way to get it work to install WAMP or LAMP (Windows/Linux Apache MySQL PHP) stack on your computer.
what is your operating system?
If it is a windows then just download and install WAMP from here http://www.wampserver.com/en/download.php then install osDate