Hi Pete, thanks for fast reply. I've: fsui.dll, fsuipc install, fsuipc.dll and fsuipc.key, but i can't see fsuipc.log. I bought license in 2004 and i used it succesfully 'till 2016 in different fs 2004 installations, due to pc changes, formatting, etc. I have this computer now for free, it's a phenom II x4 955, so i i've installed fs2004 because processor is poor to run correctly FSX with add ons installed, meanwhile i'm buying hardware to make a new pc. After installation on this pc i installed some add ons too, and, when i ran ifly 737, a message in crt shown me a message that fsuipc key isn't correct, so i check fsuipc and i seen that copy is unregistered. After this, i tried some times to register again fsuipc through install, but nothing change :-(