I know some network administrators who have already been burned by this. Microsoft hasn't made a big deal of it, but XP Home is crippled for serious server-based corporate networking. For the office, XP Professional is the only XP version to consider.

Unlike all other previous Microsoft operating systems, XP Home will simply not work in an office network environment with NetWare, NT, Samba, or Windows 2000 servers. Period. You simply can't connect to the servers' domains or their file/print services.

Because of this, you also can't use an XP Home laptop at the office. Nor can you use Home for something as simple as retrieving mail from a protected internal e-mail server over a home Internet connection. Home has only minimal virtual private networking (VPN) with Point to Point Tunneling Protocol (P2TP) or Layer 2 Tunneling Protocol (L2TP), which won't work with many VPN engines. Indeed, Microsoft only advertises its P2TP/IPSec VPN stack in XP Professional as a VPN solution.

Even if you did cobble together a way to use Home on a domain-based network--and I'm sure someone will do it; you probably wouldn't want to use such a hack. Besides not working with domains, you can't use domain-based or Active Directory-based network administration tools with XP Home. The OS doesn't even include that basic of network administration: Simple Network Management Protocol (SNMP) support. Do you really want an administration hole in your network?

XP Home also has a built-in network security problem. It's possible on some unsecured domain networks for an XP Home system to be able to access network resources by using pre-existing network login/passwords without actually logging into the domain. Once there, the system can not only not be administered, any network resources that the XP system can access could be hijacked by anyone networking into the XP Home with its insecure Simple File Sharing. And the latter doesn't include login or password protection for system resources. Now, you might think that Internet Connect Firewall (ICF) protects this vulnerability, but you'd be wrong. With ICF up, you can't share files or printers. For practical purposes, you won't want ICF on unless it's a standalone machine connected to the Internet or playing the part of a pure Net server with Internet Connection Sharing (ICS) on a small peer-to-peer (P2P) network.

XP Home will work in P2P networking with older versions of Windows, but it has significant problems even there. For starters, XP Home will only work with a maximum of five P2P servers; it simply won't work with more than that. XP Professional, on the other hand, will work with up to ten P2P servers. If you have more than that, you need to rethink your network design.

Another problem with Home on an existing P2P network is that if you run the Network Setup Wizard (NSW) on other machines--which the program will probably ask you to do--it will attempt to make the network confirm to XP's defaults, such as the workgroup name "MSHOME," rather than use the existing network defaults. You should also forget about using NetBEUI. Though that protocol is in Home, Microsoft won't support it. TCP/IP is the only real way to go.

As for the rest of setup, it will go far better if you know your network defaults and enter them into XP's Network Setup rather than let the wizard attempt to smooth your path for you. Of course, if you're starting a small P2P network from scratch, NSW will actually make the setup run much more smoothly.

But enough of this, you get the idea. The only way you'll save money in upgrading to XP for your network is to go straight to XP Professional and not waste time on Home; there really is no place for Home at the office.