In my experience, if you set an abnormal file type to be opened by a basic program, like notepad, your computer will continue to do this to all files of that type, and may prevent other progams from accessing them. I mod Star Wars: Empire At War and did this to some of the gamefiles and my game bleached, rather than crashed. Your only likely option, and it probably isn't worth the time or loss, is to run the "factory default restore" or whatever disc that came with your system. This will wipe out everything on your system and bring it back to exactly where it was when you bought it, so the modded/notepad files will be as they once were. You should find atleast two other options before you do this, as you may lose erretrievable data and possibly invalidate your warranty. Hope this helped
