Some users that have acquired Windows Vista via the Windows Marketplace have experienced problems while installing the operating system. In fact, "problems" is a way to put it lightly. The fact of the matter is that Windows Vista fails to install altogether.

This is the case with some 64-bit editions of Windows Vista Upgrade purchased and downloaded from Windows Marketplace. For the first time in its history, the Redmond Company has made Windows and Office available for download online. But it has limited the offer only to upgrade versions of Windows Vista Home Basic, Home Premium, Business and Ultimate.

In some cases, the 64-bit Vista failed to perform the upgrade and presented the following error message: "Cannot extract Windows Vista Setup to your hard drive. Please ensure that you can create files and folders in the same folder where VistaSetupPrep.exe was downloaded."

But the true reason for the failure can be found in Windows Vista Setup Preparation (NNNNN).log. And it reads something like this:
"Preparing Windows Vista Setup...
Extracting setup files to: C:Vista Ultimate 64bit UPGRADE
Error 0x80070005: Failed to launch: C:Vista Ultimate 64bit
UPGRADEVistasetup.exe
Exiting Windows Vista Setup preparation."

This is an access denied error, due to the fact that the user is trying to execute a file that is not a valid 32-bit executable. This is why users must have Windows XP 64-bit in place before they upgrade to Windows Vista 64-bit. You cannot upgrade to a 64-bit edition of Vista from a 32-bit Windows operating system. Microsoft has a warning in place over at the Windows Marketplace: "Warning: You cannot upgrade unless you have 64-bit Windows operating system running on a 64-bit capable PC."