Windows 10 October 2018 Update is Deleting User Data For Many (windowscentral.com)
New submitter CaptainPhoton writes: I updated my test PC using the Windows 10 October Update (1809). That seemed safe enough, so I proceeded to upgrade my production PC. I just encountered an issue where everything in the Documents folder was deleted, even though I had clicked the option to keep my files. Everything else in my user profile remains intact. I am curious, how widespread is this issue? Has anyone else here encountered this issue? Some articles are starting to crop up acknowledging this failure. Citing complaints from several users, Windows Central reports: Sometimes, when you perform an upgrade to a new version of Windows 10, the setup may move the user files to the previous installation backup located inside the "Windows.old" folder. However, according to those users experiencing sudden data loss, they looked everywhere, and their personal files are nowhere to be found.
You're supposed to be keeping your files on Microsoft Cloud. If you insist on using a product in a way other than the manufacturer intended, that manufacturer can't be responsible for the results.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.