Greetings. I'm looking for advice on setting up a small network, 20-40 users, spending very little (if any) money. It's not so much the amount of money, but I'm trying to build as much of an open-source or freeware solution as possible. The machines in question have XP Home installed. I'm able to get them to join a domain through a registry modification, which is doable... I don't need the more advanced features of a domain, just the file sharing, printer sharing and central user control/authentication.

My question is this: What is the most user-friendly alternative to using Windows Server 2003 as a Domain Controller? An ideal solution would be something that could integrate into a Windows XP Professional box, as I had planned to just use an old desktop for the PDC. For now, it's a classroom environment, with about a dozen machines, but I'd like it to be scalable to at least 40-50 machines. A less-preferred method would be wiping XP and choosing a version of Linux, most likely with Samba I'd assume. Is there a port of Samba for Windows, or if not, what's the best way to run it in a virtual environment (assuming there's not a better choice out there)?

My experience with networking, active directory, Microsoft etc. is pretty good, but I've always been fuzzy on the TCP/IP maximum connections/concurrent users/server vs. workstation architecture type stuff... and my users know -very- little about computers, so it would be up to me to not only implement, but train them as well.