Because I can't recall all this stuff on demand…

After converting a physical machine to a virtual machine you will notice that the computer will warn you that the IP address you are entering (assuming you are maintaining the IP address) has already been assigned to an adapter on that system, even though you see no additional adapters installed.  This is because Windows maintains device and driver data on all the former physical components of the machine that was virtualized.  To correct this issue you need to run the following command from the command prompt:

set devmgr_show_nonpresent_devices=1

After running this command, open the device manager by typing…

devmgmt.msc

… from the command line or RUN menu.  Note that running the device manager from Computer Management will not work.  I’m not sure why.  From the Device Manager, select View, and then select Show Hidden Devices.   All of the former devices will now appear under each heading as greyed out options.  Simply right-click on them and select Uninstall to remove them.  This is a matter of good housekeeping and should be performed on all your virtual machines.