Yesterday, I finally decided to install the Windows 10 “Anniversary” update. It took a while but everything worked, of course I had a full back up prior to installation.
The next morning my logon screen was there and when I hit control alt delete, a the spinning circle began. It stayed that way for over an hour (Yes, I waited while I worked on my Laptop.), until I decided it was enough. I hit control alt delete again and it allowed me to enter my password and logged me in.
Everything post logon was normal. I rebooted and the same thing, this time about 10 minutes, a third time, again, another 10 minutes. I had enough! Tonight, I decided to look in to some forums to find a solution. Suggestions cropped up from basic OS troubleshooting to suggestion to reinstall! One forum mentioned video drives as a potential issue. I did a bit of research and sure enough there was an Anniversary update driver. I installed the driver, rebooted and like magic I was back to normal.
I lost the link to the forum post reboot, I should have saved it and added it to this post. My apologies to whom ever ran the site out there in the almost infinite internet!
I hope this helps someone.