You cannot use an upgrade key to perform a clean installation of Windows Vista from the Windows Vista DVD

This article is intended for a beginning to intermediate computer user.You may find it easier to follow the steps if you print this article first.

Consider the following scenario. You purchase an upgrade license and an upgrade key for Windows Vista. You start the computer from the Windows Vista DVD, and then you try to perform a clean installation of Windows Vista by using the upgrade key that you purchased. In this scenario, you are prevented from continuing the installation of Windows Vista.

Note In a clean installation, you completely delete the hard disk of the computer that you are upgrading. You do not install Windows Vista directly over the previous operating system.

Method 1: Run the Setup program after you use the current operating system to start the computer

When you start the computer from the Windows Vista DVD, the Setup program does not perform a check for versions of Microsoft Windows that can be upgraded to Windows Vista. To upgrade an earlier version of Windows to Windows Vista, you must use the currently installed Windows operating system to start the computer. To do this, follow these steps:

1. Use the computer's currently installed operating system to start the computer. Verify that this currently installed operating system can be upgraded to Windows Vista. To view a list of Windows operating systems that can be upgraded to Windows Vista, visit the following Microsoft Web site
   http://www.microsoft.com/windows/products/windowsvista/buyorupgrade/upgradepaths.mspx (http://www.microsoft.com/windows/products/windowsvista/buyorupgrade/upgradepaths.mspx)
2. Insert the Windows Vista DVD into the computer's DVD drive.
3. Use one of the following procedures, as appropriate:
   • If Windows automatically detects the DVD, the Install now screen appears. Click Install now.
   • If Windows does not automatically detect the DVD, follow these steps:
     1. Click Start, click Run, type drive:\setup.exe , and then click OK.
        
        Note The drive placeholder represents the drive letter of the computer's DVD drive.
     2. Click Install now.
4. When you reach the Which type of installation to you want? screen, click Upgrade to upgrade the currently installed operating system to Windows Vista.

Method 2: Use a Full Product License version of Windows Vista

If the currently installed version of Windows cannot be upgraded to Windows Vista, you must purchase a Full Product License for Windows Vista. This license will let you continue the installation after you start from the Windows Vista DVD.

To purchase a Full Product License, visit the following Microsoft Marketplace Web site:

For more information, click the following article number to view the article in the Microsoft Knowledge Base: For more information, click the following article number to view the article in the Microsoft Knowledge Base: