Ok, I've got it to load the skydata by opening a route, but the aircraft definitions are still missing. What is the file called that they are written to?

Aircraft definitions are all in the settings file in that version, and it's in the location under Documents and Settings in WinXP. Feel free to just post it here if you want us to rescue it for you and obtain your aircraft definitions.

Sorry, just can't find this file. There must be one somewhere because there used to be definitions for 4 aircraft.