I agree, it's a different recording entirely, although the rap verses are largely similar (but different recordings).
The chorus is the most obvious thing, chorus in the original is vocoder "High voltage, you can't shake the shock, cause nobody wants it to stop, check it out" and chorus in the rerecorded version is rapped "High voltage, the unforgettable sound, high voltage, bringing you up and taking you down, high voltage, coming at you from every side, high voltage making the rhythm and rhyme collide".
The other thing is that Chester sings a few lines at the end that aren't in the original "Sometimes I feel like a prophet, misunderstood under the gun, like a new disease.
The other thing about the rerecording is that it has parts of Cure For The Itch at the start, and was probably intended to crossfade with it. They took it out, probably because a version of it had already been on the Hybrid Theory EP. Maybe it was supposed to be the original closing track but they wrote Pushing Me Away at the last minute and they kept with 12 tracks for marketing reasons.
The full version hasn't turned up on any promo CDs but it's a popular thing for fans to recreate.
I wonder if there are any currently unknown internal promo CDs before the Studio Finals that include something like this.