Perhaps, but you'll find it won't work very well on MacOS X or Linux.
Or 64-bit versions of Windows - which you'll need in order to utilize that huge amount of memory you'll want. You should develop using your platform's API where necessary.
I'm fairly sure you mean "available". You should always use the platforms API to do something. For starters like Noel said the API is almost certainly more rigorously tested than your code. More importantly, should you discover a bug and/or design flaw, you can always do the fashionable thing and blame Microsoft.