Hey, since Windows x64 is becoming more popular and Vista is on the rise. The fact that these two types of systems do differ very greatly, even from stdcall->fastcall and internal stuff and memory and what have you. I think it makes sense to have two seperate sections, one for Win32 and one for Win64. Since things posted about one may not apply to the other, even if they are "backwards compatible", we all know Microsofts reputation for deprecating.

Actually from the API point of view the differences are not that much - see the examples here, the most of the calls stayed exactly the same as in their Win32 counterparts.