Vistalizator is a software tool designed to enable users to change the user interface language of Windows operating systems, particularly Windows Vista and later versions. It allows users to install language packs and switch between different languages without needing to reinstall the operating system. This can be particularly useful for multilingual users or for those who want to customize their system's language settings. Vistalizator is known for its user-friendly interface and ease of use.
Depending on your version of Windows you might be able to download official language packs from Microsoft or windows update. If not you can use a unofficial unsupported third party software like Vistalizator and a MUI for your language(remeber to check your OS's bit).
Alternate display languages are only officially supported in Windows 7 Ultimate and Windows 7 Enterprise; to change the language for these operating systems you can use Control Panel>Region and Language>[Keyboards and Languages] tab to install and uninstall display languages. Alternatively, if you do not own Windows 7 Ultimate or Enterprise you can use Vistalizator to change the language of your system.
If your computer is running on Windows Vista : >Control Panel -Clock, Language, and Region -Change keyboard or other input methods -Change keyboards -Add.. -Spanish Then you can toggle from each keyboard using Shift+Alt. Other operating systems should be around the same. Look for language/keyboard settings in the control panel.