I tried to install this, but it says that there is a problem with my Windows Installer package. What should I do?
When you have issues with Windows Installer, then the simplest way to fix them is to reinstall the actual package.
Access the following page and download the Windows Installer package: https://support.microsoft.com/en-us/kb/942288
Close all the background running apps and run the installer, then repeat the installation procedure for Microsoft AppLocale.