Norton Internet Security - upgrade and Windows 8

At the moment I'm running NIS 17.9.0.12 on a laptop with Windows 7 and a desktop with Windows Vista. Works like a charm.

 

I plan to get a laptop with Windows 8 pre-installed. Can I protect it with my current NIS or do I have to upgrade first?

 

If I can do it all with my current NIS, do I have to buy an extra key first? I'm not sure how many installations are currently allowed and since I already have it running on 2 machines...

 

Willem Vermeer