Okay, guys,
Thank you all for your input, which has been most helpful. I have eliminated about 90% of the space taken by Windows.old, a relic from version 7, for the most part. At the same time it has also eliminated a handful of other files, some of which were of totally unknown origin – again, a relic! For the record, I used the Disk Cleanup method. This went quite well, while I was out of the house for four hours. I will do a de-frag the next time I have to be out of the house for any length of time.
I am impressed at receiving the answer to my problem in less than 24 hours and that the answer worked first time! I am a happy bunny as well as being a happy devil! Thanks again.
Devil