When they got released as vista-only, a small group of people released xp patches for them, so you can play them on windows XP. i haven't tested them yet, but based on the coments from where i download the halo 2 *can't find shadowrun* xp patch, i'm guessing it should work, so i'm gonna buy halo 2 PC when i can. you can find the halo 2 patch easily on google, but idk about shadowrun i can't find that one.