duplicate name in the network.

my pc belongs to a workgroup, from a while i can’t see any pc’s around me and win xp pro. gives a alert says “there is a duplicate name in the network” i checked my ip and the dhcp and the gateway & file print and sharing is installed my networkcard is working also i have internet connection but i can’t see any pc’s in the network and can’t access any pc online by going to start menu run \\… xp tells me “the network path is not found” knowing that my internet connection through a dsl linked to 2 switches and every user in tha workgroup has his own name but dynamic ip address… what do i do ?