Norton Subscription

Hi,

I recently bought Norton Internet Security 2009 3 User. Which i installed on my laptop. I just have a question about the subscription.

I have N.I.S 2008 on my desktop which is halfway through it's subscription and another laptop which has N.I.S 2007 and has just had it's subscription renewed.

 

I was wondering if i installed N.I.S 2009 on both the laptop and desktop, will the subscription of N.I.S 2009 add onto the existing subscription or overwrite the existing subscription?

 

An answer from a Symantec employee would be greatly appreciated.

 

Thanks