Since the last time I was able to switch to another user, in my 1st computer, only Windows Defender Definitions were installed.

Currently, I'm not able to switch to another user: the computer slows down so much that 10 minutes are not enough to complete the operation. The disk activity LED, which is normally on in these operations, is off most of the time.

Nevertheless, I'm able to log off current user, and then, log on another user.

ADDED: I ran sfc.exe /scannow, but it only found 2 corrupted files, which are remanent from last failed KB3022345 installation: "utc.app.json" and "telemetry.ASM-WindowsDefault.json" (from CBS.log).

• Edited by __arpoador 2 hours 39 minutes ago included sfc /scannow result