If you having Windows 8 or Windows server 2012 installed and you think you have the wrong language or you want to have a different language than you can change this.
You should go to your configuration screen. ( Currently my Windows is running a Dutch version)
Go to the option Language. (The word Taal is Dutch for Language)
Click on add a language
Now you can select a language to add to your windows.
When you click on Options you can choose to download the language pack and install the selected language pack.