You can give network places a shot. If both PC's are in the same workgroup and the initial network wizard has been run it might work. Network Places is basically garbage without a local DNS or WINS server however. In lieu of that, or instead of that, just use the UNC path from the run box.
Start, Run. Then type the path. ex If host machine is server and the shared folder you shared is named netshare the path would be \\server\netshare You could also use the IP if NetBIOS isn't working well. So instead of server you'd just use the IP and the share name. Of drop the share name to see what is actually shared on the remote machine.