I have been trying to get the XPs on my network to share
their files and folders with other computers on the
network for some time to no avail. and I believe that I
have exhausted all of the suggestions provided on TechNet.

I can see the XP on the network. I can ping it. It can
access the files on the other computers. However, none of
the other computers are allowed access to it's files. It
says 'Invalid UserName or Password'.

The UserName is in the XP's list of users. The TCP/IP
protocol is the sole File Sharing Protocol and NetBios is
enabled. Lastly, ICF is disabled.

What else can I try?