Cable Forum - Protection for 2nd pc

I have norton anti virus where i am ment to be able to protect 3 differant computors.
On my computor i have windows vista , I have just bought my son a new lap top for his birthday which has windows 7.

As i am ment to be able to use the anti virus on 3 computors i have been trying to install this on my sons new laptop.

I have tried installing the disc in his lap top but just get the message that this vertion is not suitable for window 7 .

So i go into my account with norton which shows up i have 2 more computors i can install my product on and even states its been updated to be ok to install on window 7 .

But theres nothing for me to click on to be able to do so , i have googled this and followed other instructions to do this but i dont seem to have all the links appear that others are saying should appear.
I dont wont to buy another anti virus if im ment to be able to use the one ive allready purchased.
I have also scanned the norton site to see if i can e - mail them to ask them directely but cant find a section to do so.
Has any one else had this problem . If so whats the solution.
Many thanks