I have a PC that is connected via ADSL router to the internet. I have another PC and a Laptop that are connected wirelessly via this internet connection. When I log on to my main PC I get a message that says "Duplicate Name Exists on the Network". I can't work out where this duplicate name is or how to find it. Please can you tell me what to do? Also my PC, the main one, is very very slow- could this be a reason for its being slow or should I look for something else.