Apache Friends Support Forum

I have an application developed in CodeIgnetor frame work in php 5.3.0 and MySql 5.1 and hosted on win server 2008 server. This application gets hang for 8 users on the server envoirnment but works fine on XP professional for same number of user with less hardware configuration. Any guess why it is happenning. Please respond your fedd fack. It's urgent.
on XP machine Xampp basic 1.7.2
Apache 2.2.12
My Sql 5.1.37
Php 5.3.0

on windows server 2008

Xampp 1.7.3
Apache 2.2.14
My Sql 5.1.41
php 5.3.1

Hi Guys,
Send me your opinion and thoughts.