Here's how to configure a computer keyboard for Spanish language letters and characters.
Instructions for PCs (Windows 7/Vista/XP):
click on Start button in task bar
click on Control Panel
click on Clock, Language and Region
then in Region & Language, click on Change keyboards or other input methods
click on Keyboards and Languages tab
click on Change Keyboards
in Install Services, click on Add button
scroll to Spanish (Spain, International Sort)
click on plus symbol to the left
then click on plus symbol next to the word keyboard
check the box Spanish
click the OK button, then click the next two OK buttons that appear
After adding the new keyboard configuration, to change between English and Spanish, hold down the LEFT Alt key and press any Shift key. Some computers will give you a language switch option in the lower right of the task bar.