Details

Why do I see an error message that "The IP address XXX.XXX.XXX.XXX..." is already assigned to another adapter?

Solution

Under certain conditions, you may see this error message from a Windows guest operating system:

The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter Name of adapter. Name of adapter is hidden from the network and Dial-up Connections folder because it is not physically in the computer or is a legacy adapter that is not working. If the same address is assigned to both adapters and they become active, only one of them will use this address. This may result in incorrect system configuration. Do you want to enter a different IP address for this adapter in the list of IP addresses in the advanced dialog box?

In this message, XXX.XXX.XXX.XXX is an IP address that you are trying to set and Name of adapter is the name of a network adapter that is present in the registry but hidden in Device Manager.

This can occur when you change a network connection's TCP/IP configuration from DHCP to a static IP address if:

  • You have upgraded VMware virtual network adapters (for example when you migrate a virtual machine from an older to a new version of VMware software.)

  • You have added and removed network adapters multiple times.

--> The rest of the answer is on VMware KB : http://kb.vmware.com/kb/1179