It would be very rare if whatever is acting as the DHCP server on your network is handing out the same IP address to a second node on the network, so you would need to look for a network node (that would be anything from a networked printer, xbox, TV, laptop, smartphone, desktop, etc., that for some reason has a manually assigned static value for IPv4 properties. As a remedy you could either configure that device to also obtain its' IP address automatically or if that is not an option you could make sure that whatever that IP address is it is either excluded or reserved from the DHCP scope of the DCHP server (which is probably your Router) often you can look at the DHCP client tables from within the Router's interface and that might give you a clue as to the device that is causing the problem, but if it is statically assigned then the device will likely not appear there.
When you get that message on your problem computer, just open up a command prompt and type
ipconfig /release
and hit enter
wait a brief moment and type
ipconfig /renew
and see if that doesn't resolve the problem.