In some rare cases an "Error 1721. There is a problem with this Windows Installer package" may occur while installing Studio 12 or a Studio 12 patch on Windows Vista. Below is image showing the error:
If this error occurs, make sure that you have installed all of the available Windows Vista updates from Microsoft and they try the installation again. There was success internally with installing the following update to resolve the problem.
Update for Microsoft Windows. (KB950124)
It would be a good idea to make sure that you are fully updated however with all available Vista updates before attempting to install or patch Studio 12.