How many times can you use your key ?!

How many times can I use my key for NIS, I mean can I install NIS as many times as I want or can I only install NIS a few times, I thought it has nothing to do with how many times you install on the same computer NIS but that it looked if it was the same system ?!

I ask this cause I have a key for 3 years that was delivered with my HP computer..

 

Here I read that one user had the experience: http://community.norton.com/t5/Norton-Internet-Security-Norton/Problems-with-Activation-Key-and-new-upgrade/td-p/688449

 

 

 

"After entering the product key, it said that we had exceed the maximum installs and had to purchase another Product Key"

 

^^ This is strange !!