Its not as if there is any 3D involved its only directdraw stuff, has the DD/2D side of it changed that much?.
Yes, in Vista it no longer exists.
Have a look at this article and bear in mind it was written in June 2001 (2 years after Baldur's Gate), 7 years ago!
Having standard's that don't change is fine but when the whole industry is moving as fast as the gaming and graphics industry has over the last 25 years then it's unrealistic to expect hard and fast standards so that a game written 10+ years ago will work correctly on a completely different platform. On the hardware side the cards we use today are barely recogniseable compared to those we used in the late 90's.
You don't need an emulator, if you've still got an old PC or a copy of your old OS simply load it onto an old disk and away you go. Or use a VM, Microsoft Virtual PC is a free download...
Darkheart