We have 1x XP Home PC and 2x XP Pro PCs. One XP Pro PC is connected to a Cable Modem (Card#1) and Local network (Card#2) providing Internet Access to the two other XP computers via ICP (Windows Internet Connection Sharing). So the PCs are not on a Domain.
While XP is a joy to use, we longed for the days of Win95 where you could setup a simple home network with no guest password prompts and everyone could share root folder and printers with no fuss.
How to start the windows "Group Policy Editor"
If you try to log onto Windows XP Professional with classic file sharing (Simple File Sharing disabled), without a password, you normally get an unknown error 31. To enable logon with no password find the following policy and Disable it.
Note: Windows XP Home does not have a Policy Editor.
What I had to do was Add the same account to the PC2. eg. If I'm logged into my Main PC as Administrator "Robert" then I have to also add an account "Robert" (Administrator & No password) to PC2.
and add the user as an administrator
Comment from Paul Nashamkim:
When I switched my home network to XP ages ago, I found that I couldn't share anything (files, printers) until I set the same password to each account on each PC (even though one was set up as Administrator and one as Paul (with administrator rights). I just wrote it off to my own stupidity for not finding some obvious setting, and since it worked fine, I forgot about it.