Yes, Hagar, that is the little brown box about which I speak. How do I get back to the earlier icon of the blue pages like you see when you open a file with Notepad? Is it really all that important? I see periodic references to changing the .air file. I also see that it is best left to the professionals. What exactly is in the .air file? What effect does what's in there have on how the model behaves?
The easiest way to revert to the original icon would be to uninstall Adobe AIR from Start/Settings/Control Panel/Add or Remove Programs. However, if it was the Notepad icon there would be no point as you cannot edit FS AIR files in a text editor or any default Windows program. It will do no harm to leave it as it is. AIR file editing has always been a black art to me. It was more important back in the days of FS98 & CFS1. Most FD editing can be done in Aircraft.cfg these days.