Glaucus these things happen when you start playing around with mods. But I can't see why just coping RTW would stop you loading a save, unless you've applied RTR or some patch to the original RTW, rather than the copy. When you install RTR etc, you can change the directory you install into but by default it is like to be your original RTW. Can you load the save on your copy?

If not, I think you have two choices. First, just uninstall everything and start again. Tedious, but reliable and probably necessary in the long run. Second, pass on the savegame, if you can't face playing around with installing etc. Personally, I'd recommend option (1), bur make sure you find a good book or something during the wait.