A Microsoft file hosting and synchronization service.
I had the same issue. There was a syncing issue, I resolved it, then every file on my Desktop vanished. It looks like Microsoft is giving me the "user error" brush off. I did manage to find a few files in the C:\Users\profile name\OneDrive folder so thanks for that. How Microsoft can write programs that wipe your local C: drive without warning in an unrecoverable fashion. Here's a thought, if you're going to do stupid stuff like that, how about just sending it all to the recycling bin so that it is recoverable if it wasn't intentional? As with everything, Microsoft knows better. I'm sure my business didn't need all of those contracts and data that you just deleted. Oh, and of course the syncing wasn't working correctly either so the only backups that I truly have are the ones that I had made to other drives. You wonder where this gets to the point of being a class action sort of issue. The program is obviously defective and they advertise it as a set it and forget it type of service.