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 Windows System event log.

This is the only computer I have so there's no way any other computer can have this. Also, my phone has been having trouble connecting to my WiFi, even though I keep uplugging/plugging in my modem to try to fix it.

I have never gotten this message on my computer either.

Does anyone know what could be the problem here?

Did you try turning it off and then on again

All jokes aside, I did that and then I got this message.

I've gotten that once or twice, never affected anything that I noticed.

That happened to me when I was fixing my xboxes NAT type to Open. I assigned it a static IP but then my PC was on random and it was randomly selecting the same one as my xbox and then it would clash. So I had to give everything in my house a static IP or they would select each other for some reason.

Maybe they were trying to mate.

on your router, there should be a "device list" page or something similar, and on that page, there should be a button to release all dhcp reservations (or something like it). look for that and click it.

This.