Thanks for your response Pete. The registry key appears to be "Installed To"
I had already tried copying FSUIPC.DLL into CFS2 Modules folder but what happens is when you select FSUIPC from the drop-down Modules menu, it runs outside of CFS2 and CFS2 freezes and has to be closed with Control/Alt/Delete. The FSUIPC.LOG recognizes the FSUIPC Key alright and apparently runs a number of processes but is not useable, here's a copy of the LOG:
********* FSUIPC, Version 3.998g by Pete Dowson *********
Running on Windows Version 5.1 Build 2600 Service Pack 3
Verifying Certificate for "C:\Program Files\Microsoft Games\Combat Flight Simulator 2\MODULES\FSUIPC.dll" now ...
SUCCESS! Signature verifies okay!
Running inside CFS2
User Name="Anthony Pleasants"
User Addr="plea727@telus.net"
FSUIPC Key is provided
WIDEFS not user registered, or expired
Module base=61000000
LogOptions=00000001
DebugStatus=15
813 System time = 21/11/2011 13:10:27
813 C:\Program Files\Microsoft Games\Combat Flight Simulator 2\
16891 System time = 21/11/2011 13:10:43, CFS2 time = 13:10:42 (13:10Z)
21891 ERROR: Can't change message filter: functions not available
25563 AIRCRAFT\F4U1A_CORSAIR\F4U1A_Corsair.air
25563 Aircraft=""
25875 SITUATIO\defgnd.flt
25922 Clear All Weather requested: external weather discarded
26172 Advanced Weather Interface Enabled
26172 Not patched ADVDRV.DLL since offsets don't match!
26172 SIM1.SIM patched for more accurate altitude holding
89344 WeatherOptions set, now 00000001 (timer=0)
131547 Aircraft=""
131703 SITUATIO\defgnd.flt
131750 Clear All Weather requested: external weather discarded
131860 SIM1.SIM patched for more accurate altitude holding