How to Detect IP Address Conflict on the Network
Each device connected to a network is assigned a unique IP address to identify it to the network. When one IP address is accidentally assigned to more than one device, an IP address conflict occurs. If your computer is using an IP address that is conflicting with another device, you will get a pop-up error telling you that the system has detected a conflict. To find out where the conflicting device is, check the system log for your computer and look up the conflicting device's MAC address by using the IPconfig command.
View Your System Log
Access the Control Panel on your computer by clicking the green "Start" button on your desktop.
Select "Administrative Tools."
Select "Event Viewer."
Look through the log for an entry that mentions a DHCP error and note the MAC addresses of the devices involved.
Look Up the Device
Reach the command prompt by clicking "Start," selecting the "Run" option, typing "cmd" and pressing "Enter."
Type "ipconfig/all" at the command line and press "Enter."
Find the MAC address in the IP configuration table that appears. This device is the one that has been assigned a conflicting IP address.