[eps]

> Microsoft are free to change the Native API at will,...

But they won't, because if there is one thing that Microsoft has always been extremely good at and cared for is backward compatibility. And changing Native API will break a ton of existing software, because even though undocumented it is very widely used.

[blibble]

you are confusing the ntdll interface (which is undocumented and subject to change), and win32 (which is stable, mostly)

they tell you not to use ntdll, and say they will change it whenever they want

and they have in the past

(they have had to moderate this policy with "containers", but it's still what they say)

[eps]

I'm not confusing anything.

[dbdoskey]

Actually they do change the native API quite a bit. Not in minor releases so much but in major releases

[eps]

They depricate some methods (very rarely and reasonably) and add new enums or struct versions to existing ones, but never change existing semantics, leave alone method signatures. As I said elsewhere, I invite you to find examples of actually destructive Native API changes.