If you plan to use both Boot Camp and the Boot Camp partition as a Virtual Machine then you need to do WPA (Windows Product Activation) once under Boot Camp and then again while running the Boot Camp partition as a Virtual Machine however you need to have VMware Tools installed before you do WPA in the Boot Camp partition as a Virtual Machine if at all possible otherwise you'll end up doing it again after VMware Tools is installed.
In some cases Users have had to call Microsoft to get an additional Product Key in order to activate Windows again and this it typically with Windows Vista not XP once it has been activated to many times.
You can, as an example, explain to them that you have one physical install of Windows on one physical machine and also want to run it as a virtual machine on the same physical machine without having a second install and they might be willing to help you however the bottom line is this whole WPA issue can sometimes be a pain in the _ (fill in the blank) however aside from having VMware Tools installed to handle WPA in a Boot Camp partition Virtual Machine and switching back and forth running Boot Camp natively otherwise this is really not a Fusion issue as long as VMware Tools is doing its job otherwise it is between you and Microsoft.
