Replace the "POP3.exe" in the game directory with the patched "POP3.exe" given in the zip file. Take backup of the original file. Registry error wont happen in steam or GOG versions, But in case it happens, load "PrinceOfPersia.exe" in config mode by pressing Ctrl and then load "POP3.exe". The save editor named "timeline3.exe" helps change secondary weapon durability, health, sand count, sand powers unlocked, location, character, sand credits of a particular ".SAV" file