Hi,
this is what I did by now:
1. I deinstalled my HO2 version using the deinstall command from the
startup menu in my laptop
2. I reinstalled the original HO2 version
3. I installed patch 1.3a (Sorry, I was unable to find a 1.3 benchmark patch
anywhere, could you please tell me where to get such a patch?)
4. I installed patch 1.3b (AI patch)
5. I copied the backups of my savegames into the savegame folder
6. I launched the game and continued the last savegame of my Japan 1941
game. Soon, the "fate of China" event fired and I did not get a CTD
again!

That was great! Again thank you very much for your support!
However, after I continued gaming for a couple of hours, I tried to attack a Redchina Army. My attacking armies had full strength and full organization. Curiously I did not see any battle screen (not even for a few seconds), but immediately got the message that I lost the fight. My armies did not loose any organization or strength but had to reorganize. Thereafter I attacked again. The same thing happened. I loaded my last savegame (of course after the "fate of China" event) and the same thing happened again. This has never happened to me before (and I played the game for a long time).
Any ideas of what I might have done wrong this time are most welcome
I have read the "you must read this before posting" and the stickies. I am happy to provide the required information about my system next time. Unfortunately, right now, I am not using the same computer.