After you enter the product key and then click Next in the Windows Vista Setup Wizard, you may experience a long delay. This delay lasts about 20 to 60 seconds.

When you insert a Windows Vista 64-bit DVD within a 32-bit operating system, and setup is launched, the operation is unsuccessful, and you receive the following error message:

Setup cannot run on this version of the Operating System. To install Windows please try booting from the install media.

When you try to upgrade a computer’s operating system from the 64-bit version of Windows XP Professional (x64) to a 64-bit version of Windows Vista, the upgrade is disabled.

Note: If you have a 64-bit version of Windows Vista installed, you can upgrade to an allowed 64-bit version of Windows Vista. For example, you can upgrade Vista Home Premium to Vista Ultimate.