PC to PC

I can't link up my XP to my Vista Home Premium computer. All service
packs installed. Each computer can see the other but I can't access the
XP's shared folder. I am using cross over USB cable and have installed
drivers for same.

I get message trying to access my XP from my Vista pc - "folder is not
accessible. You may not have permission to use this network resource."
"Not enough server storage to process this command"

I have granted access on the XP to share this folder.

Is there a simple, 1,2,3 step by step process to ensure that I have met
all necessary criteria to make a pc to pc connection?

Many thanks