Accessing Network Places and Messenger services

I just installed mn-510 and I can acces the internet, but
cannot get into the other computers in my house. I can
see them in my workgroup, but every time I click on them
I keep getting the message saying:

"Computer01 is not accessible. You might not have
permission to use this network resource. Contact the
administrator of this server to find ut if you have
access permissions.

The network path was not found."

Also I can't get into any of the messenger services. I
use MSN Messenger and everytime I try to sign on, I get a
message saying that I it cannot connect because I'm not
connected to the internet. But I am connected to the
internet, otherwise I couldn't be writing this message
right now.

Can nybody out there make sense of this. I'm fairly
knowledgable about computers, but this just completey
confusses me. I would really appricaiate any advice that
could be given. You reply to this post or just eMail me
directly at (E-Mail Removed)

Thank you