Since applying the registry edit given by ClitheroeKid my live.co.uk email account has worked perfectly in WLM 2012 on Windows 7 laptop. I have monitored it for 5 days and it has been fine. Today my 4-block IP address changed and everything continues to be fine at present. Long may it continue !
A huge round of applause for ClitheroeKid and my sincere, grateful thanks.