Quote - It's the same thing with running 16 bit processes under 32 bit windows; the operating system handles all the necessary mode switches automatically.  Probably the main reason that 64 bit windows can't handle 16 bit code is probably because the added complexity it would entail isn't worth it, considering that 16 bit is about as obsolete as it gets.

64 bit CPU can switch to 16 bit mode or even DOS mode, Microsoft only want to force people that still are using Windows 3.1 or DOS applications to trash these applications and purchase a new fresh and if possible MIcrosoft product.
There are many DOS and Windows 3.1 applications that still are used and there's no need to upgrade them, they are working fine, fulfill their purpouse and are integrated into standart procedures.

Stupidity also evolves!