Where did you install the game, and do you have other Steam games in the same folder? Steam defaults to a "C:\Program Files (x86) \Steam \SteamApps \common \Silent Hunter 3" folder, which is a Windows "system" protected folder, so any changes made there without proper pre-approval from the OS will be rolled back for all cfg and other files. Most of the graphic files are unaffected. You can then end up with a nasty "mod soup" of SH3 that does not function at all. See
How To Move A Steam Game... for a couple of methods of doing such. If you have a valid 2nd hard drive partition that you can put another Steam Library folder in, that is the easiest and fastest way. "Fast" in this case is a relative term though. The 2nd thing about SH3 (and SH4) is that the game runs off of the Save folder, and if you do not clear that after a mod change, you will again have a mix of mods that usually does not function correctly. This is usually the "C:\Users \UserName \Documents \SH3" folder. Delete its contents and run the game again. It will re-create the folder, but with the new data of the mod. You will lose all previous Saves and the user settings you've applied to the game's interface.
