NOTE: If you need to type in a password to even get into Windows to do the following, make sure you attached an external keyboard first, to get past the password. Then disconnect the external keyboard and try the following...
1. Uninstall the keyboard driver.
2. Reboot the computer (without reinstalling the driver).
3. When it restarts, it should reinstall the driver on its own.
If this doesn't work, you may wish to try connecting/reconnecting an external keyboard and see if it works fine. If it does, then it could be the keys themselves that are the issue.
Additionally, if your device uses one, you may want to try updating the Synaptics Driver if the above doesn't help.
You may also want to check the device for malware, viruses, etc., which can interfere with normal operation.
You may also want to look at In Windows 10...
To add a keyboard language...
1. Click the "Start Start" menu and select "Settings".
2. Select "Time & language".
3. Click "Region & language" in the left column.
4. Select "Add a language".
5. Choose the language you want to add and select a country for the language.
To set a default keyboard layout...
1. Click the "Start Start" menu and select "Settings".
2. Select "Time & language".
3. Click "Region & language" in the left column.
4. Under "Languages" click the language you want as default and click "Set as default".
To switch keyboard layouts...
Option 1...
1. Click the "language name" in the lower right of the screen (taskbar).
2. Select the keyboard layout you want to use.
Option 2...
Press and hold the "Windows" key while you press the "Space bar" to change the language.