Vista-style transparent windows in XP

I've already tried this on a small (32 MB integrated graphics card, 512 MB RAM) computer running a pirated version of XP/SP2 (as it happens, it's very difficult to find a home computer that DOESN'T have a pirated version of XP here in Brazil where I am right now).
Anyway, although it works for sure, it really slowed everything down on this machine to make the computer almost unusable. So, I had to turn this effect off.
In any event, it really wasn't so wonderful that I just had to have it.