Thanks for your replies. It was purchased via download. I have tried copying the download onto a disc, but have had difficulties. Is there any problem with using the product key again for making the back-up?
With my order confirmation came the advice 'We recommend you save the download to an external drive or DVD'. This is what I have been trying to do, unsuccessfully (on to a CD). If anyone has done exactly this (copying the download from my desktop) perhaps they could guide me through step-by-step. Is it the installation package that I should be copying? Many thanks.