can't figure out why computer see other computer on the Local Network

I have three computers in the local network. Two are XP professional and one
is XP home. My Laptop which is XP pro can't access the two other computers.
But the other two computers can access my laptop. The other XP pro computer
can access my Laptop and the XP home computer. My Laptop is the only
computer that is being screwed here. I don't know why this is happening.
When I double click on the computer that is on my workgroup but it gives
me this error "\\Rwalnut is not accessible. You might not have permission
to use the network resource. Contact the administrator of this server to
find out if you have access permissions. The network path was not found."
Can anyone help me out here


Ankit Shah