Hi,
Refer the following article in order to uninstall any additional languages installed on the computer.
‘Windows 7 language packs are available for computers that are running Windows 7 Ultimate or Windows 7 Enterprise’
Refer **‘How to uninstall a Windows 7 language pack’**to uninstall the additional languages.
http://support.microsoft.com/kb/972813
Also refer the following link for more information.
‘Install or change a display language’
http://windows.microsoft.com/en-US/windows7/Install-or-change-a-display-language