Yep. Most of the small companies I've seen just use the Windows DNS servers because they need them for AD. You can set up separate DNS servers and delegate AD's

Yep. Most of the small companies I've seen just use the Windows DNS servers because they need them for AD. You can set up separate DNS servers and delegate AD's domain to the domain controllers, but then you're maintaining additional DNS servers. And besides, most of the small companies I've seen vastly prefer a Windows GUI than (e.g.) configuring bind on the command line.