For those with vast libraries of files and documents be warned
representing millions of hours of work ... there is growing angst at
the latest October Win 10 Update deleting personal files. There does
not seem to be a discernable pattern yet apart from the only folders
reportedly left untouched have a OneDrive icon. Reports are that many
users have lost many gigabytes of personal and business files -
documents, pictures, music and video files all deleted; and files in
Desktop too.

Whilst Win 10 has been reported as randomly deleting files since 2015
this latest snafu is far far worse. And Win 10 Home users can do
nothing to avoid this. Pro users can at least delay the update.

Opinion on the web is that MS has deliberately caused this to force
users to use OneDrive - at cost.

Files may - only may - be recovered - RECUVA is one recommended app.
But in other cases files are gone, lost forever -  unless backed up.
But even backups to say USB hard-drives appear to be affected by the
earlier 2015 snafu.

And - it has been going on since 2015 ...

To say MS and Windows stinks is an understatement.