Windows 8.1 operating system is not English. How to chang

I purchased an H.P. ll-in-One with Windows 8.1 installed. I specifically stated I wanted the op system to be in English. It isn't .
The control of the computer is in Hebrew. Some, perhaps most of the applications are in English.
I need to know if and how I might change the operating system itself to English.
I have searched the Internet for a solution, but they all were referring to the language packs. I don't need a language pack, I need the system itself to be in English.
Can this change be made?

Use this tutorial to change the display language if possible:
http://www.eightforums.com/tutorials/5853-display-language-change-windows-8-a.html

You could also talk to where you bought the computer that you did not get what you wanted.