Many thanks for your prompt reply. That has given me something to think about. Am I right in thinking that I can de-activate it on my desktop computer when I am going on holiday and activate it on my laptop for the duration of my holiday and then re-activate it on my desktop when I return. The only time I use it on my laptop is when I am on holiday away from home, maybe once or twice a year?
This would certainly solve my problem as I could then use the other activation on the office laptop and leave it on there for when I go into the office.
Following on from that, how do I de-activate it when needed? Thank you for your patience.