A pc in my Microsoft Windws Network

Ok people…When I open Windows Explorer (I use win 2000) I click the + next to Entire Network. Then I click Microsoft Windows Network. There are now 2 listings. There only used to be one. This new listing seemingly just appeared and is listed as a special charachter, a square to be exact. So when I click on it, it says, “is not accessable, the parameter is incorrect”.

Please help!!!