PLEASE STOP SCREAMING
Ok, it is not necessary to have any protocols other than these in network properties, I have no idea why they would want to over complicate something so simple;
Client for MS Networks
File and Printer Sharing
TCP/IP
For XP Pro, disable simple file sharing (Explorer, tools, Folder Options, enable simple file sharing unchecked), put both computers in the same workgroup (right-click My Computer, properties, computer name), and have unique names (PC1 PC2, etc). Make sure that you have identical user accounts on both PC's with the same passwords. Share something, done.
For simplicity, dont run the networking wizard, it can do funky things like bridge your firewire port to your network card and other junk, absolutely unnecessary.