Consider the following scenario:

• You are running a Windows Vista-based computer in a network environment. There are multiple computers in this network.
• You assign or change the IP address for the Windows Vista-based computer. You do this either manually or by using an application.

In this scenario, you receive the following error message about a network error that concerns duplicate address detection (DAD):

Windows has detected an IP address conflict. Another computer on this network has the same IP address as this computer. Contact your network administrator for help resolving this issue. More details are available in the System event log.

Additionally, the following event is logged in the System log:

Event ID: 4199
Event Source: Tcpip
Event Type: Error
Description:
The system detected an address conflict for IP address  with the system having network hardware address . Network operations on this system may be disrupted as a result.