Upgrade from Windows Vista to 7, re-installing NIS

I recently upgraded from Windows Vista to Windows 7.  I am using NIS on my computer, and I had just updated to NIS 2011 on Vista.

 

The problem is, when I upgraded to Win 7 it erased NIS from my computer.  You can use NIS on up to 3 computers, and I am the 3rd computer (ie. I don't have the disk to re-install).  I am still the 3rd computer being used but because of the upgrade, there is no Norton on my system (the changeover from Vista to 7 must have deleted it).  Thus I can't go into Norton Update and get a new program to download - since it shows "no Norton procucts installed on your system". 

 

The question is:  how can I get NIS back on my computer? 

 

Again, nothing has changed, it's the same computer I've been using with NIS all along, it's just that the new os has deleted Norton. 

 

Any help would be appreciated.