No, you only need one unlock code per GPS receiver. You can use the software on as many computers as you like.
I installed CN on my laptop but I only see main road, why?
You still need to enter the unlock code for your GPS. You can either enter the 25-digit unlock code manually, or you can export the code from your desktop and import it on the laptop. All this is done through the 'Unlock Wizard'.
Thanks Jay, my problem is fixed with your help.
Best regards