Ok so if you go into Network places and then select the workgroup can you see each PC?

When I do this on my laptop, It shows only 1 computer and it appears to be the laptop. When I do this on the desktop computer I get the following error message:

"Home 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 list of servers for this workgroup is not currently available."

I am the administrator, so why it would say this I don't know.