Colin Barnhorst wrote:
Where do you get the idea that MS chose not to let the clients "go
there." They inherently don't "go there." The only "choice" MS made was
to program a capability into the Windows Server editions that enables
them to "go there." The capability to enable PAE to leverage additional
addressable memory is something that has to be programmed into an OS,
not something that is programmed out of one.

Okay, again. You said it yourself: both xp and vista comes with a PAE
kernel, to support DEP.

When you enter PAE mode the CPU makes it both mathematically and
technically possible to address more than 4GB. So now the OS developer
has a *choice*. Microsoft choose *not* to support more than 4GB in the
PAE kernel (starting from XP/SP2), because there exist bad drivers out
there. *This* is what we're talking about, at least I am.