Home Networking with Microsoft Windows

I have been setting up a small network at home with machines running different versions of Windows (WinXP Prof, WinXP Home, Win2k) and it took me a while to figure out the proper way to set up file sharing. This is in a configuration with a Domain Controller. In that case security will be limited to only two account types, Admin and Limited. And under 'Simple File Sharing' the guest account is used for all access from a different machine. So you need to make sure that the guest account is Active, but not necessarily allowing it to logon. That is done using "Net User guest /active".
Steve Winograd shows this on his 'Windows Networking Myths' page http://www.bcmaven.com/myths.htm . He also makes the point, that under this sharing regime, there is no need to explicitly share out folders.
There are also several KB articles discussing the security and file sharing.
This one is excellent: How to Configure File Sharing in Windows XP
On XP Prof you can disable Simple File Sharing: How to disable simplified sharing and set permissions on a shared folder in Windows XP

Also, it seems that you need to disable the MS "Internet Connection Firewall", which is done with a control panel applet "firewall.cpl". Steve Winograd above has some old articles at PraticallyNetworked which explain this in detail.

Here is a quote from the first MSKB article below:

Verify that the Internet Connection Firewall (ICF) or Windows Firewall (WF) feature is not enabled on the adapters that you use to connect the computers to the home network. If these features are enabled on these adapters, you cannot connect to shared resources on other computers in the
network.

And this is from the second article:

After you enable an Internet firewall, you may not be able to search, or "browse," for other computers on your home or office network, and you may not be able to share files with other computers on your home or office network. For example, when you enable the Internet Connection Firewall (ICF) feature in Microsoft Windows XP, you find that you cannot browse
your network by using My Network Places. Also, if you use the net view \\computername command to view shares on a computer on your home or office network, you may receive the following error message:

System error 6118 has occurred. The list of servers for this workgroup is not currently available.

Relevant MSKB articles:
How to troubleshoot home networking in Windows XP
Internet firewalls can prevent browsing and file sharing