Validate product after clean upgrade to Windows 7 from XP

I just upgradef from Windows XP to Windows 7 and was told by the installation program that I had to do a clean install, which as far as I can tell has simply wiped the hard drive and installed a Windows7 where windows XP used to be.  This has worked just fine and I have downloaded and installed Norton Internet Security which also worked fine.   I now have to validate the new Norton install.  I have a multi-PC license for the product and I want to make sure that Norton doesn't use one of my remaining activations when I validate the new install as it is on the same machine and I can no longer use the installation on windows XP (as that was deleted from the hard drive along with the OS).  How can I make sure I don't lose one of my remaining license validations?