Wrong keyboard input language on Windows 8 lock screen

In you Control Panel (Desktop Mode), there's the way:

Control Panel\All Control Panel Items\Language\Advanced settings

You will see a link in the first section called:

  • Apply languages settings to the welcome screen, system accounts, and new user accounts.

Click on it, it will open a dialog window with two (2) sections. In the first one, click on Copy settings... then check the two (2) checkboxes in the bottom of the resulting window. Then OK. It will apply your current settings to the lock screen and etc.