Please HELP... this message just keeps popping up!

This is the error message that keeps popping up:

 

There is an IP address conflict with another system on the network...

 

Now I am no IT Anything but what I get from this is that another computer is hacking in my network and is this even possible while using Norton 360 doesnt this suppose to stop things like this or am I wrong????

 

All advice appreciated    :womansad: