Jetfreak

Hi!I've reinstalled the LVLD 767 for FSX in Windows 7. I have Windows XP running on the same computer as well, where my flight simulator had previously been installed. When I want to start FSX now, an error occurs, telling me that there's a problem with the activation of the 767. I still have the proof of purchase and all that stuff, but how can I reactivate the product?Thanks for your help in advance!!!