I purchased paid version of VMWare VCenter from VMWare.
I originally installed it on Windows 2008 Server (which was a virtual machine within the same VMWare server) and added the license code to use it. All worked fine.
Then I determined that it was not a smart move to install the control program (VMWare VCenter) on the very same VMware server. So I installed it on another server box dedicated for Windows 2008 STD only, however after installation, I can't seem to find the "Copy existing Virtual Machine" option in the VMWare VSphere Client for some reason. It was nice to be able to make a copy of existing virtual machine right inside VSphere Client. Also I can't add additional VMWare box to this VCenter. I have a couple of more VMWare boxes that I use for testing and I was able to add additiona VMWare boxes (with different IP address).
Please see attached for VCenter Client and the screen shot of the main menu. Off the main menu, I installed VCenter Server and VCenter Client.