Thank you, mta. Following your instructions, I was able to remove that old ccleaner64.exe file in Safe Mode. I then successfully downloaded and installed a new installation of ccsetup531.exe .
Now I have additional questions. Previously, for several years, I have simply analyzed and then removed whatever the analysis found, not really paying attention to what it was removing. I am now thinking that was not very smart. In looking at the items the analysis just now found, I see the Recycle Bin is listed. I don't like to remove recycle bin items until at least a month has passed so will remove that item from deletion. I am wondering what effect some of the other deletions might have - is there a site, or forum thread or some place to look for suggestions as to what to delete and what to leave alone?
Thank you for your help. This is a valuable forum (though, to your credit, I have not needed to request your help before)
........sherri