Thanks for so kindly following my case and sending quick answers.
About FDC :
As suggested by you, I have installed the start program -Flightdeck_Companion.exe- in the main FDC directory.
The program answer was rather puzzling: I needed a post version 2.00 program to use this command - currently it is 3.14.
Next trial was even worse: nothing happened - no message, nothing and no trace in the Windows tasks Mgr.
I could circumvent the FDC issue by calling the FDC_Accum314.EXE program and it worked OK. Keep my fingers crossed
A little remark:
I noticed that departure transition altitude and the destination one are alike (both use the departure one) whatever was written in OPTION - MISC ITEMS - Airport values. I though that this was included in one of the previous fix ?
Impossible to add or modify aiport data... pity as many have change name or new ones are replacing old airports (indonesia for example). I use the nearest one.
Have tested PFE main program with a restored adventure (.ADV, .BRF, .GPS) and it perfectly worked.
Problem being thus limited to PF2000 adventure compilation, I have installed the base package on my wife's Win8.1 PC (maybe I shouldn't tell you that).
I transferred a brand new FS2004 pln file and I could compile it without any problem in WIN8.1 environment.
Problems arrived later when trying to tune the flight plan in PFE - some Win8 inconsistency I guess.
Because of the paranoid WIN8 programmers, I took me half a day to find the .BRF .ADV and .GPS files and, finally after digging everywhere, I was able to transfer these back to my old XP SP3 PC.
And guess what ? I found back all my flying friends
About the restore now - I will buy a new HD soon:
My data are split on 2 separate HD's
Drive C : with OS, MS applications and FS9 base package and plenty of other rubbish (ADE, AFCAD...).
Drive D : with most FS sceneries (many, many and more), PFE, FDC and PFPX mainly.
Which disk should I start with for restoring... I prresume C:- Yeap?
Again, thanks for your patience.
George C. Henman.