Dominic, without bothering you too much, this is my installation log....Thks
INSTALLATION FOR FSX:
SetupPath="C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\"
Checking version of FSX.EXE:
... Version 10.0.60905.0 (Need at least 10.0.60905.0)
Checking compatibility with installed SimConnect:
Found SimConnect build 60905 (Original)
Found SimConnect build 61242 (SP1 May07)
Checking if there's already a version of FSUIPC4 installed in:
C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\Modules\FSUIPC4.DLL
... Version 4.853 found.
FSX Modules folder already exists.
Okay -- installed FSUIPC4 into "C:\Program Files (x86)\Microsoft Games\Microsoft Flight Simulator X\Modules\FSUIPC4.DLL"
Looking for the current user's Application Data path:
... found as "C:\Users\Gros loup\AppData\Roaming"
Now finding \Microsoft\FSX\FSX.CFG for all users, including this one
Looking in "C:\Users\Gros loup\.jenny\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\aircraft\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\AppData\Roaming"
Found FSX.CFG in "C:\Users\Gros loup\AppData\Roaming\Microsoft\FSX\FSX.CFG"
Now checking DLL.XML ...
... There is a previous DLL.XML, checking for FSUIPC4 section.
... FSUIPC4 section already exists but will be replaced.
(for FSUIPC4, without Loader)
... FSUIPC4 section of DLL.XML written okay
Now checking for a SimConnect.XML file ...
... There is a SimConnect.XML, checking for "local" section.
... "local" section already exists, file not modified.
Looking in "C:\Users\Gros loup\Application Data\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Contacts\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Cookies\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Desktop\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Doc\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Documents\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Downloads\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\effects\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Favorites\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Links\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Local Settings\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Menu Démarrer\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Mes documents\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Mes fichiers de sauvegardes\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\modules\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Modèles\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Music\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Pictures\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Recent\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Saved Games\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Searches\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\SendTo\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Tracing\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Videos\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Voisinage d'impression\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\Voisinage réseau\Roaming"
... No FSX.CFG there
Looking in "C:\Users\Gros loup\x64\Roaming"
... No FSX.CFG there
"Modules\FSUIPC Documents" folder already exists.
Now installing additional files into the "Modules\FSUIPC Documents" folder:
Installed "FSUIPC4 User Guide.pdf" okay
Installed "FSUIPC4 for Advanced Users.pdf" okay
Installed "FSUIPC4 History.pdf" okay
Installed "List of FSX controls.pdf" okay
Installed "GlobalSign Root.exe" okay
Installed "FSUIPC Lua Library.pdf" okay
Installed "FSUIPC Lua Plug-Ins.pdf" okay
Installed "Lua License.pdf" okay
Installed "Lua Plugins for VRInsight Devices.pdf" okay
Installed "LuaFileSystem.pdf" okay
Installed "Example LUA plugins.zip" okay
Installed "Offset Mapping for PMDG 737NGX.pdf" okay
FSUIPC4.DLL installed and signature checked out okay!
Deleted GlobalSign Root fix program ... no longer relevant
===========================================================
All installer tasks completed.
Registration for FSUIPC4 was cancelled or failed! (result code 40)
*************** End of Install Log ***************
Late to the party, but I note that you're not using the current service pack for FSX or SimConnect (SP2 or SP3, if memory serves) Gian. Can I suggest you get up to the current version on both (even though it's a pain to do)?