Networking Xp Pro

I have a laptop and a desktop, both running XP Pro with SP2, ihave the two PCs networked together (with a crossover cable) They can se each other , they can ping each other but the laptop cannnot access the desktop, the fire wall is off on both,when i try to access the desktop i get an error message
“desktop not accessable.You might not have permission to use this network resource. Contact administrator of this serverto find out if you have access permissions” ” Access Denied”
I am just fresh out of ideas.