Does my laptop have two 800MHz processors or two 1.6GHz processors?

When a processor has "hyperthreading" built in, it fools the Operating System (in this case, Windows) into thinking there are two separate cores, when in fact there is only one. Hyperthreading is basically a very streamlined and efficient instruction pipeline that can theoretically almost double the amount of work a processor does per clock cycle, so Intel decided to include microcode to fool the operating system into thinking there are two cores, and get the OS to use two threads on it at the same time. This takes the most advantage of the hyperthreading ability, versus just one thread at a time.