Can't install Windows 7 Professional on a MacBook Pro running Parallels 6.

The Mac already has a licensed Windows XP Professional on it. Despite this, installation of Windows 7 aborts and gives a message that there must be a pre-existing licensed MS product installed on the machine.

 

Windows XP is installed on a virtual hard disk of a virtual machine? Are you installing Windows 7 to the same virtual machine or a new virtual machine? If to a new virtual machine, did you add the virtual hard disk of the XP virtual machine to the new virtual machine or duplicate the XP virtual machine's hard disk for the new virtual machine to use?

 

Windows 7 is a new virtual machine. How do you add the virtual hard disk of the XP virtual machine to the new virtual machine, or duplicate the XP virtual machine's hard disk for the new virtual machine, whichever is the correct action?

 

Select the virtual machine in the Virtual Machine List. Right click and select "Show in Finder". Right click the .pvm in the Finder and select "Show Package Contents". Select the .hdd and copy it to outside the .pvm (hold option to copy it).

Then in the new virtual machine -> Configure -> Hardware. Click [+] to add a new hard disk, select existing image, navigate to the .hdd to add it.