windows 10 (October 2018 update) (version 1809) deleted all my files

I have problem with onedrive from ver 1807. I contact with sp microsoft but they don't slove my problem. And ver 1809, a lot of people lost file with onedrive :V

Trying to work out from your pics where the update moved your books folder. (Updates shouldnt even be MOVING users data folders let alone deleting them!)

Its not clear but your books folder is in the /user directory (the area of concern), correct?

The links had been removed?(like feature update 1709)

The books folder moved, where did it move to? Was it hidden?

So all you had to do was create a new shortcut to it?

UPDATE: Version 1809 pulled from Media Creation Tool as of 9:52 PM PST Friday. I think it might be due to this issue since we've heard nothing on it from Microsoft yet. 

The Version 1809 Update has been withdrawn.  If it's pending here's how to abort it:How to Cancel Pending Installation of Windows 10 Version 1809.

If you have it installed you can roll it back if it's causing problems at Settings > Update & Security > Recovery, or wait for corrective Updates to be pushed to solve reported issues.

A report here today that files were found in online OneDrive Recycle Bin feeds one theory in my possibility checklist at the beginning of this thread that OneDrive has force-enabled in it's Settings for many users Files On Demand so the files only live in the cloud and are only chosen to download from links on the hard drive.  This should be only a consumer-selected extreme space saving measure,

Then add to that the File Protection sync selections in OneDrive settings Auto-Save tab are force-enabled for Desktop, Documents and Pictures folders,

So if those folders now only live in the cloud and an Upgrade occurs, where are they sync'ing to afterwards, if at all?  Maybe into the Recycle Bin.  So check there.

Windows Update can ONLY update. It cannot remove your personal files and folders without being instructed to do so. This is not hard to comprehend, I hope.

Now you may have malware or hardware problems that have caused files to suddenly disappear. Anything from a Trojan to a hard drive failure.  You all might want to run some checks to see if any such issues show up.

You can begin by running the Windows Memory Diagnostic:

You can also open the Command Prompt (CMD) and run SFC /SCANNOW as well as DISM

Just copy and paste either of these commands in the command line:

DISM.exe /Online /Cleanup-image /Restorehealth

DISM.exe /Online /Cleanup-image /Scanhealth && DISM.exe /Online /Cleanup-image /Restorehealth

The second line runs two checks and repairs consecutively without further input from the user.

Also as I previously suggested check C/Users for missing files and/or folders thusly:

I should mention that my "Books" file (where I keep all my pdf files) had apparently vanished with the update since it was not where I had left it. At least, the shortcut was useless. But I soon located it and pinned the new location to quick access.

I like knowing where my books are 😁

PCR Just PCR,

Actually, no - OneDrive is disabled for this computer, so there is no OneDrive Recycle bin.

I store all files locally, and backup locally with portable drives or thumb-drives.

I prefer my data not be spread all over the internet, for security concerns.

I did just enable it, to see what would come up, but I don't expect that to resolve my lost files. 

I didn't think of that. And I see the upgrade didn't turn OneDrive back on for you. I'm glad the mishap of deleted files didn't happen on all of your computers. I wonder, did your Documents folder have more than 5 GB in it on the computer that failed? What about the others?

Do you already know...?...

https://www.seagate.com/support/software/dashboard/

Dashboard Support

It's supposed to be so simple to recovery files, a few clicks... 

http://knowledge.seagate.com/articles/en_US/FAQ/006148en?language=en_US&key=ka030000000irsvAAA&kb=n&wwwlocale=en-us

Seagate Dashboard - Installation, Backup, Verify, Restore, and Features

"

Restore Process

1. Make sure that the drive is detected by your computer.
2. Launch the Seagate Dashboard software by double-clicking the Seagate Dashboard icon.
3. From the Home screen select Restore
4. Select Search for backups

Note: This may take a while depending on the size of the backup but you will want to let it run until complete so all the backup dates will be available. 5. Next you will be asked to Select File - Select the date you wish to restore from and then select the data you are wanting to restore. 6. Next you will be asked to select where you want to restore the data.

Note: The original location is only suggested if the computer has the same system and user name as the original backup. If either of those are different, you would want to restore the data to the desktop or alternate location, then copy the data to the new/correct location.

"

I really don't know what it means by "system name", but did you try restoring to an alternate location? Did it give you an error message? Here is an article with a few of them...

http://knowledge.seagate.com/articles/en_US/FAQ/006139en?language=en_US&key=ka03A000000aujXQAQ&kb=n&wwwlocale=en-us

Seagate Dashboard - Troubleshooting

But nothing really good in there.