Von Liben
Just to ensure a successful install, ensure that your IL-2 BAT game is NOT installed into your C:\programs folder. The game needs to be anyplace else but not in the programs folder. Also, I recommend that before installing BAT on top of your ver. 4.12 game, make a copy of the game. This is a simple thing as you only need to do is add a new folder outside of your IL-2 folder, name it something like "Clean Il-2 ver 4.12" then return to your current game folder, select all of the contents of that folder (all files and folders) select copy, return to your "Clean Il-2 ver 4.12" folder, then paste everything into that folder. The end result will be two complete Il-2 ver 4.12 games on your system. Now here is the reason why - we all at some point will break the game and the easiest thing to do is start over. You now have your clean game ready to go, no need to re-install and patch to 4.12 because it is already there. Secondly, you may decide that you are interested in another MOD (such as VP Mod) or decide to go to ver 4.13. Now you can add these versions to your inventory with ease. Keep in mind - never change your "Clean Il-2 ver 4.12" folder, this is your foundation to your IL-2 world. When you want to add a different version of the game, all you need to do is create another folder, name it as you like, copy the contents of the clean game folder and paste it into the new folder. It is in the new folder where you make your changes.