From login screen (log out if you are logged in):

1. Tap the “Accessibility” icon
2. Disable “Sticky Keys”
3. Tap “On screen keyboard”
4. Tap “Shift”
5. Tap “Power” icon
6. Tap “Restart”

After the restart:

1. Tap “Troubleshoot”
2. Tap “Reset your PC”

After the restart:

1. Tap [Next]
2. Tap either “Just remove my files” or “Fully clean the drive”

The option depends upon what you need to do.  If you don’t know the login password, you will need to fully clean the drive and start fresh.