i have just bought a brand new 500gb HDD installed windows sp1 64BIT on it from another computer and the install went fine booted up and everything was normal, so I plug it into my laptop and it boots into start up repair and start Windows normally, so I press enter on start Windows normally and then the laptop restarts (endless loop) I don't know which BIT my laptop is supposed to run on I think it is 64bit but I don't know