Hi again 'adamf', I ran command prompt as per details provided and left the PC for some 45 minutes to have tea. When I returned it was already completed with a successful 'Refresh Image Created 0f some 13+GB'. So it didn't take long at all. I've also bookmarked the tutorial so that I may refer to it again as and when required.
Once again Windows Eight Forum and it's members (as did Windows 7 Forum) came to my rescue. Thanks to all concerned.