Yes! I discovered that today after several hours of contemplation and testing. I renamed the new files the game created and restored the old files and compared them. The only two I could look at were the cfg files. So I began with the obvious one - the main.cfg - and badah-bing, badah-boom; I'm back in the saddle. I then restored the DGUI 1920x1080 mod and it worked. I've saved and exited and shut down the computer several times to ensure it works and it does. The only logical conclusion I can come to is that either the replay.tmp or save.tmp files (binary files) were corrupted when I exited the program on the 25th and why the game would not start on the 26th.
I would like to give a big thank you for all of you that tried to help me resolve this problem. It is greatly appreciated. Now back to patrolling the cold waters of the Atlantic.
