The most recent patch is 1.10c. I've linked it below for you. It's all-inclusive so it should install over 1.04 or earlier, without issue.
http://ageoddl.telechargement.fr/BoA_patch1.10.exe [LEFT]Once you have this file downloaded, simply launch it. Pay attention to the destination folder, typically
C:\Program Files\Birth of America, though it may be different in your case. The important thing is that the destination points to where BoA resides. If you still have trouble updating to this latest build, post back here. We'll get this sorted out.[/LEFT]