Difference in Response times with Different LoadGenrators. Why?

I recently encountered this issue and the below solution fixed this issue

Issue:
The response times of transactions for the users generated from a Load Generator on Windows 2003 are lower then the response times of the same transactions from Users generated from a Load generator on Windows 2008 R2

Solution:
Perform this on Load generator on Windows 2008 R2

1. Control Panel> User Accounts >Turn User Account control on or off> Uncheck the Check Box with Name: User Account Control Box On to protect your computer

2. Add SSL Certificate:

a. Go to Fire Fox that is in the Bin dir (if it is for Ajax True Client)
b. Open it> Tools > Options>Advance>View Certificate> Add Certificate
c. How will I get Certificate?
Play the application manually on this box. Then certificate may be downloaded in that location.

3. Turn Off Fire Wall