Do you have fs2002 installed?.i know some dont have this problem but thats the same message i got when trying to have both on my hard drive.so i uninstalled fs2k2 and no problems.

perkins.i would contact microsoft and get yourself on there waiting list for help.then come back here to the fourms and list your system spec.and while you wait on microsoft.knowing more about your system will help to maybe solve the problem.you can see what i have listed below my post to give you an idea what you would need to list about your computer.but between microsoft and the fourms your problem should get solved.but list every thing you know about your computer.
 

 

Go to this site and click on contact microsoft.you will halft to have a net passport if you dont have one just sign up for one its free.then just follow the information from there.

http://support.microsoft.com/

It should be in some of the paper work that came with the sim have a look in there for this number its asking for.