Re:Vista Home (Score 1)

32bit systems don't have enough addressing space for 4GB of RAM, cuz 2^32 - 1 = 4,294,967,295. This space is also shared with other hardware. It's not because Windows is poorly written. Microsoft can't just turn on a magical switch that lets a 32bit OS see all 4GB of RAM.

Yes, they can. The person you were replying to even spelled it out for you.

Three times.

It's called PAE.

I call red herring! PAE doesn't involve magic at all!

Seriously, Windows XP SP2 and forward run in PAE mode for NX or XD processors. However, Microsoft limits access to 4GB for driver compatibility reasons.