Moderator Notice@Jim Reid - please don't post the same issue more than once - I've merged your posts from the other thread. See ==>>
MR Guidelines
If Safe mode doesn't cast any light, and you're using 3rd party AV/FW I suggest
uninstalling them - you may need to download a 'special' uninstaller from supplier to do that. Disabling doesn't always remove everything (services) nor does Safe Mode.
BR