Just to make sure, you go to Start> Run (or Windows Key + R)> \\(IP address of LS) ... this should bring you to the shares, what do you see there (if it even gets that far)?
Also, go to the properties of your local area connection, and make sure that you have "Client for MS Networks" and "File and printer Sharing" both enabled.
Turn off Windows Firewall as well any other software firewall (most anti-virus software has one).