CI and IIs

[eluser]suzie[/eluser]
Dear Friends,

am working on a new website using code igniter, now I want to see it online, so I moved it to the server, where using IIS...in a folder called new-site, new-site contains the APplication folder of CI

now when trying to link to the folder to see the site online, www.example.com/new-site

I received the following error on IE:
This error (HTTP 500 Internal Server Error) means that the website you are visiting had a server problem which prevented the webpage from displaying.

For more information about HTTP errors, see Help.

and on FF:
PHP has encountered an Access Violation at 011F6FC2

any help please , it is very urgent

Regards,