I am trying to install SugarSuite_for_Microsoft_4.5.0c on a Hosting provider's server (that uses Plesk7.5). I am trying to install against PHP, IIS, SQL Server version 7.0. At Step 7 of the install I get the followig error:

Creating Sugar configuration file (config.php)

Creating Sugar application tables, audit tables, and relationship metadata...


Fatal error: Cannot instantiate non-existent class: mysqlmanager in C:\Inetpub\vhosts\mymangotree.com\subdomains\sugar \httpdocs\sugarcrm\include\database\DBManager.php on line 173

It looks like DBManager if trying to instantiate class mysqlmanager instead of mssqlmanager. I looked in config.php and db_type is set to NULL. Is this causing the problem? I do not know how this got set to NULL. What is db_type supposed to be? I am totally stuck.
Thank you so much for your help.