Transfering subscription to other machines.

Purely as a favour to an ex-colleague I maintain the families Pc's on a basic level.

 

They have the 3 machines they are allowed on the subscription for internet Security 2011 which they upgraded to earlier this year.

At the time they took advantage of the reduced subscription for 3 years.

 

Now they tell me they are going to buy two new machines. disposing of one of the old machines and giving me their currrent top machine which I built for them 2 years back.

 

So I am anticipating a dilemma when they get their new machines.....because the 3 year subscription they have for the 3 machines they want to transfer to the 2 new ones !!

 

Can anyone tell me how to make this a painless transaction....I fear the worst.