I have no idea how it happened. I have recently downloaded the Creation Kit for Skyrim, and I've overwritten the files I was asked to overwrite, in the Script and Script/Source folders. Now, the game opens far more slowly (too much slowly), and not only that, but I also can't play the game at all, since it crashes every time I try to load a savegame. Now I'm going pretty crazy, trying to figure out by myself what happened, and how to solve it, but I'm afraid that I can't really jump to a conclusion. If anybody could help me, it'd be really, really appreciated. Thanks to anyone who might want to help me.