Are Microsoft's IE Images 64-bit or 32-bit?

Are Microsoft's Internet Explorer Application Compatibility VPC Images 64-bit or 32-bit? For example, if I were to download the Windows Vista with IE7 image and then install IE9, would it be IE9 64-bit and 32-bit or just 32-bit by itself? You would think this information would be shown somewhere on Microsof开发者_运维问答t's site, but I'm not seeing it.

Since they are built for Microsoft Virtual PC as stated in the article, these would all be 32 bit only as Virtual PC only supports 32 bit guests.

I believe it's a universal binary that contains both, but will install only the 32bit version if you're on a 32bit host. By default, Vista/Win7 will both start the 32bit version anyways, since most plugins (especially Flash, until v11 is actually released) have not made the jump to 64bit yet.