Your lucky, ive lost everything and theyve made changes in the way they do updates, and appeared to have fixed the glitches. Alot of this has to do with the NEW Security Intelligence updates and the Defender
Application and conflicts with Cloud and Toolbars.
I just installed the 20236.1000 update, and I had my first serious problem. It may, or may not, mimic your situation. I have 5 HDD's and 1 SSD. 1 HDD is a 1TB 2.5" in an enclosure. I mention that because, here's what happened:
I ran the update routinely as I have all of the other updates, and it ran flawlessly..., or so I thought! After logging in there was no desktop. I use 3 monitors and the backgrounds are managed with gPhotoShow, with a folder of pics of classic cars. Well,
after logging in there was 1 '63 Galaxy 500, white over red, fastback, and it was on all 3 monitors. That's not supposed top happen. But what else was happening was a message "Please insert a disc in DVD RW D:". I also have 2 DVD RW in the system. But even
more notable was that there were no icons on my desktop. I did a lot of GOOGLE searches, and there were MS answers.microsoft.com sites with solutions that were completely NOT helpful. So, I got ThisPC to display my drive inventory and I noticed something different.
I had tried opening files from the icons in the Start menu, but I would get another strange message that the files (Word files) could not be found at D:\Documents\xyz". Before the update, D: was a 4 TB HDD that houses my OneDrive files. That drive had been
renamed, and searching with the new drive letter wasn't giving me any love. So I opened Disk Manager and renamed the drives the way they should've been named, and now, all is well.
This may have nothing to do with what was going on with you, but I put this out there because it is update related, just in case.