[squarefoot]

A system restore from an image would wipe everything, luckily all user documents were intact, including user login, password and desktop background. But all personal data pertaining to 3rd party browsers was gone (all passwords, all bookmarks) which suggests that an algorithm decided that something in the user folders had to stay and something else had to go.

[colemickens]

Sounds like Windows 10's "Fresh Start" feature. https://www.microsoft.com/en-us/software-download/windows10s...

I could easily imagine someone stumbling onto this and running it. (Windows Security -> Device perf & health -> Fresh Start).