Installation choices for consumer versions of Windows Vista bit only Content provided by Microsoft Applies to: This article does not cover bit operating systems. For more information about installation choices for bit versions of Windows Vista, click the following article number to view the article in the Microsoft Knowledge Base: The method that you use to install Windows Vista depends on the answers to the following questions: Do you have an upgrade license of Windows Vista or a full product license? Does the version of Windows that is installed support an upgrade to the version that you purchased? Do you want to preserve your personal files, settings, and programs? Or do you prefer to perform a clean installation of Windows Vista? More Information General information about how to install Windows Vista Definitions Upgrade to Windows VistaAn upgrade to Windows Vista preserves the currently installed personal files, settings, and programs. You can upgrade only certain versions of Windows to certain versions of Windows Vista. Custom installation clean installation of Windows Vista A custom installation or clean installation of Windows Vista does not preserve the currently installed personal files, settings, and programs. Windows Vista is installed without third-party programs. You can perform a custom installation of Windows Vista by using either an upgrade license or a full product license. However, if you own an upgrade license, you must start the installation in the current version of Windows. At the installation choice menu, select Custom to perform this action. The upgrade version of Windows Vista An upgrade version of Windows Vista is a license that lets you install Windows Vista if you already own a compliant, licensed version of Windows. You can perform either an upgrade installation or a custom installation of Windows Vista by using an upgrade license. However, you must start the Windows Vista installation in the compliant version of Windows. This article discusses upgrade options when you are running a bit operating system and you are trying to install a bit version of Windows Vista.