This is what i been hearing. its takes about 700 MHz to just run windows xp while it takes about 2.0 MHz to just run windows vista or windows 7. Before i say anything else, lets say we have the three operating system at 3.0 MHz each. So i come to idea that if its taking 2.0 MHz just to run windows 7 or vista as compared to 700 MHz just to run windows xp, then i'm assuming that out of the 3.0 MHz, only 1.0 is really being used up for speed for windows 7 or vista since 2.0 is already being used up just to run either system as opposed to windows xp only using 700 MHz just to run the xp system having about 2.3 ghz left over for speed. This is my theory speaking. Is that how the systems work? am i right? I only ask all of this is because i'm considering getting windows 7, 64 bit edition. But if I'm going to be sacrifice more MHz (speed) just to run the system alone and less being used for speed and since MHz can only be around 4.0 max on most home computers, then i rather just settle for windows xp for that reason alone. that's of course if that's the case.