Lots of people have a 64 bit CPU and don't really even realize it, because their computer came with a 32 bit OS installed.
Notice though, that like 25% of Vista users are running x64, compared with a very tiny percentage of XP users (because XP 64 wasn't exactly made widely available, whereas it's included in the box with some editions of Vista)
Notice though, that like 25% of Vista users are running x64, compared with a very tiny percentage of XP users (because XP 64 wasn't exactly made widely available, whereas it's included in the box with some editions of Vista)