TOM 30/10/2019,
t's true that you have to reinstall all of the updates again and ensure that get KB4490628 and KB4474419 installed as they deal with the change of SHA 1 to SHA 2.
( neither of these are installed on my win7 and what is SHA 1 to SHA 2)I recently factory reset my Win 7 machine and had problems with the updates until I found a download to manually download/install the first of those KBs - I'd already got the second of those through Windows Update but the error code of 80092004 pointed to a SHA problem and to ensure both of those KBs were installed.
You could do as you suggest in booting into Safe Mode first, but that may not tell you if the program is starting the Credentials Manager service.
(I did the install of w.r 4.6 in safe mode, but still won't boot back into safe mode, so I restored back prior to of the install)I always create a system image as well before I test run new versions of the repair program should things go awry as I don't trust restore points.
The repair program may fix whatever is wrong with your system, but the bcd not being found and occasional problems with F8 could be related and as a sfc /scannow came back clean, then I would favour a repair install.
Ray,
PS I see when I go to Microsoft download centre the following-
https://windowsreport.com/Windows Report › kb4474419-kb4490628-kb4484071
Download Windows 7 KB4474419, KB4490628, and ...
Mar 14, 2019 - If you want to receive future security patches on your Windows 7 machines, you really need to install KB4474419, KB4490628, and KB4484071 ...