How to fix Someone else is using this PC in Windows 10

 

Someone else is using this PC
  1. Press Windows key + I to open Settings.
  2. Select Accounts, and then Sign-in options.
  3. Under the Privacy section, unselect the Use my sign-in info to automatically finish setting up my device after an update or restart option.
  4. Repeat the steps on all the accounts on your computer.