Config Error on different iis version?

I am getting the this error message

HTTP Error 500.19 - Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.

Module: IIS Web Core 
Notification: Unknown 
Handler: Not yet determined 
Error Code: 0x800700b7
Config Error There is a duplicate 'system.web.extensions/scripting/scriptResourceHandler' section defined  

I have migrated a site from one server(iis6) to another(iis7) and when running on the new server I get the error in question. I cant seem to find a solution to this anywhere? Can anyone shed some light?