Description of problem:

When a student presses keys, the corresponding letters do not match what they type. This occurs regardless of what website or program they are using.

Solution

The keyboard layout has been changed from the default English(US)

Detailed steps to set the keyboard back correctly:

To check the keyboard layout, click on the bottom right corner (the 'system tray' with the clock and wifi indicators).

 
In the row of setting buttons, look for the Keyboard option and click the small arrow next to the word 'keyboard'.

You may see other keyboard languages/layouts here. if it does not say "English (US)" you should set it to English. If you don't see another keyboard listed here: click on the "gear" in the top right of this menu. This opens the main keyboard settings window.
 

In this window click on "Add input methods"
 
You will then get a list of keyboard layouts. At this point, choose "English(US)". then back in the "Inputs and keyboards" window, click the "x" to the right of the keyboard with the incorrect layout