My Photoshop 7 installed without trouble for me in Win7 64 Ultimate. No compatibility modes. Straight install. I've never tried CS. PS7 (with Imageready) does everything I need.

Expert in computer code including, but not limited to, BTW; IIRC; IMHO; LMAO; BRB; OIC; ROFL; TTYL. Black belt in Google-fu.