Is it possible to remove demo banners from demo fsx aircraft?

YES

for demo tools visit demotoolsfreedownload blogspot.

Check the registry editor and looks for the title of downloaded application and delete them. Basically you have to delete everything what the program left behind. Once you do, you have the power to...

no you must buy it in the orange box. or you can buy it on the PC sepratly you need to have steam though.

Nope, it will not.