[bitcrazed]

> You would be hard pressed to find DOS-era software that bangs on buffer starting at 0xB800:0000 that still works in 64-bit Windows.

True, though 32-bit editions of Windows still include NTVDM which runs Win16 apps!

Microsoft is pretty fanatical about backward compatibility.

Why? It's the #1 reason most enterprises and many users continue to pay to install/upgrade to Windows.

Breaking backward compatibility with existing executables (not source-code) is a violation of the trust that we've earned with customers for the last 40 years or so.

Of course, some products/features/etc. are discontinued on newer OS', etc. but the core essential platforms are rarely discontinued.

True fact: Windows still runs VB6 apps - millions of them. EVERY DAY!