Having trouble emulating MS FS 2004

For some reason i cant seem to emulate disc four and enable it to play without the actual disc in the drive. I have a sony dru-710a. I have tried to mount the disc four image with alcohol and when i attempt to run the game it gives me this message, “Cannot locate the cd-rom, Please insert FS2004 Disc 4, select ok and restart application.” I have also burned the disc 4 image to a CD-R, and tried to play it but it gave me the same error message. am i doing something wrong here? I have searched the forums, and i havent found anything that works.unless i missed something any suggestions welcomed.

Microsoft Flight Simulator 2004 - A Century Of Flight
SafeDisc 2.90.040
Disc 4 only

Where did you get the images from?