One of the most clear error messages you'll ever see - it means there's
another computer on your network with the same Internet Protocol address.
If you are on a home network and you assign static (fixed) IPs to your
machines - you've duplicated one. If you'e on a network where addresses are
automatically assigned (DHCP), then the likely culprit is a machine that was
turned off, its IP reassigned by the server, and the machine came back on
line thinking it still had a valid IP.

Right click Network Places (or Control Panel/Network Connections), right
click on your network connnection, select Repair.


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