Whatever drive you installed on that'll be where the files are. So if you installed it onto the f: drive (VISTA) thats where the save games will be as well. Inside the f: drive. If you now install the game onto c: drive (XP) you'll create new files and a empty save folder inside the c: drive. The only way to get your old save files is to go to your f: drive and copy them over. Pretty sure thats how it works on a dual boot system.