Lost Internet Connection after Installing Parallels

Hi,

i lost internet connection even in Mac OS after installing Parallels. at times, there's pop-up msg in Mac OS that reads

"IP Configuration
192.168.1.100
in use by 00:99:cc:f5:58:c3
DHCP server 192.168.1.1"

any idea what goes wrong?

Thanks

 

Another computer in LAN is using that IP address, try to change IP on another Computer, this is not upgrade issue.