I was recently asked how to activate the U.S. International keyboard in Windows 8. Here are some resources that might help.
The process is similar to previous versions of Windows, but to quote How to Geek Com:
There is a small change to the Control Panel in Windows 8 that involves splitting the Region and Language applet into two separate applets.
Don’t forget that the US-International keyboard is an option under “English (United States)”.