Yes, the Windows TCP/IP stack was from BSD. I'm not sure if the code is still in Windows, but I think it is still configured via an etc/hosts file. I believe the BSD licence was preferable to Microsoft (as it was to Apple who based OSX on BSD). The networking stack was supposedly better on BSD than Linux too, but I'm not sure how correct that is (but I did hear that the software company I set up a website for in the mid 1990s switched from Linux to NetBSD pretty much as soon as I left for that reason).