are you still trying to install SP4 to your original Falcon4 sim ?
If you are, have you done the following changes.........
Note; After installing Falcon 4 from CD,and BEFORE installing patch; In the Falcon ZIP directory RENAME
the Tacrdata.zip file to Tacrdata_old,this will fix a bug in the 1.08 file; then RENAME back to original file name
Then go a head and in stall SP4.
Life has few rain checks so don't put off the important things.