While running the virtual machine on new mac for first time, you will get a prompt with 2 options
Moved and copied.
You must choose moved it. This ensures that you settings especially mac address of the VM remains same. This also avoids activation of Windows and few windows programs.
Hence now i can give 2 suggestions.
1) activate the programs / windows by contacting microsoft.
or
2) If you still have your old Mac, transfer the virtual machine bundle ( located at ~/documents/virtual machines/ ) again and open the bundle with Fusion.
When you get a prompt, choose moved it.