I have a domain in my WAN group that shouldn't be listed, for some reason it just appeared I have no idea what it is Im thinking it might be a users laptop or something. Is there a program I can download to track this unknown domain down? for security reaons I need to take care of this ASAP.
Double-click that domain in the Network Neighborhood, then run nbtstat -c to show the cache which should give an IP address for that domain's MasterBrowser (unless WINS is involved).