Thanks for the advice G0ULI.
The new HP laptop arrived this afternoon (23 hours from order to delivery!) and I'm very pleased with it. I'm quite surprised at how light and thin it is. Less than half the thickness of my old Toshiba with four times as much storage.
Further research seems to indicate that Windows Mail/Live Mail is not available for download anywhere since Microsoft discontinued support earlier this year so I followed your advice and set up the W10 Mail client. All seems to be working fine so I've just got to get used to the new interface and import all the old sent and received emails and the contacts, but that's a job for tomorrow.
Thanks again for your help.